The script is formatted with self.options dictionnary.

For example :

  [foobar]
  recipe = slapos.recipe.build
  foo = bar
  script =
    print '%(foo)s'

Produces :

  Installing foobar.
  bar

But this can mess up the python code, because there's no
escaping. For example :

  [foobar]
  recipe = slapos.recipe.build
  foo = bar's
  script =
    print '%(foo)s'

Produces :

  While:
    Installing foobar.

  An internal error occurred due to a bug in either zc.buildout or in a
  recipe being used:
  Traceback (most recent call last):
    File "<string>", line 2
      print 'bar's'
                 ^
  SyntaxError: invalid syntax

We can workaround this by using :

  [foobar]
  recipe = slapos.recipe.build
  foo = bar's
  script =
      print '%%s' %% self.options['foo']

But every percent sign has to be escaped. That's why, this
commit introduces :

  [foobar]
  recipe = slapos.recipe.build
  foo = bar's
  format = no
  script =
      print '%s' % self.options['foo']

NB: This commit doesn't remove formating for backward compatibility.

- Do not use a property for a local variable.
- Use new-style class.
- Stop using logger.
- Save a few getattr calls.
- Do not keep references to buildout & options outside of __init__ .
- Convert mode in __init__ to detect errors early.
- Factorise several accesses (buildout['buildout'], properties)
- Drop redundant "cache" download.Download parameter: it is automatically
  fetched from first parameter internally.
- "Backward compatibility with other recipes" is just not "backward".
- Return downloaded file path, not just the optionally-created directory.

Squashed commit of the following:

commit 275d6e017f06a6a1a038cd1543b3b08f21448178
Merge: 4234290 319c7223
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Thu Sep 8 15:20:10 2011 +0200

    Merge branch 'master' into suggested-improvements

    Conflicts:
    	slapos/recipe/build.py

commit 42342905ad325eefa921de1bc814dd74505ea131
Author: Antoine Catton <acatton@tiolive.com>
Date:   Thu Sep 8 15:12:11 2011 +0200

    Minor: use shlex to parse patch options

commit 7994dcc87afd528ea405c57e2c441b9424018863
Author: Antoine Catton <acatton@tiolive.com>
Date:   Thu Sep 8 15:11:21 2011 +0200

    Buxfix: the patch wasn't send in stdin

commit ee8f324921c7675c764f1c1e05eecf4c1da225f7
Author: Antoine Catton <acatton@tiolive.com>
Date:   Thu Sep 8 12:04:22 2011 +0200

    Use shlex to split command line

Squashed commit of the following:

commit 506d815ff7e1d7b7b5b3c5edcfcea744c5b2201e
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:54:59 2011 +0200

    Support multiline values.

commit c5d9415000fb072a07164bbdd5c276e53470b265
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:48:54 2011 +0200

    Fix compatibility layer.

commit 1e301c7ba51060d944fea9ff2be1aba00e3a48b6
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:41:41 2011 +0200

    Go back to development.

commit 9f523c49
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:40:00 2011 +0200

    Prepare 0.5 release.

commit fcaf5c04
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:39:28 2011 +0200

    Be more compatible.

commit 5284491f
Merge: 2d7dc0b3 f15bb155
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:28:40 2011 +0200

    Merge branch 'master' into cmmi

commit 2d7dc0b3
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:22:13 2011 +0200

    Explain more about patches.

commit d5df4cdc
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:18:55 2011 +0200

    Provide better looking patches.

commit c6befb05
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:15:32 2011 +0200

    Support make-command and make-options.

    Fix configure-command.

commit d2212cb7
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 17:04:05 2011 +0200

    Allow to override configure command.

commit 4321b38a
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:56:49 2011 +0200

    Share applyPatchList with in base class.

commit 4a2ea3b3
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:56:29 2011 +0200

    Support no md5sum.

commit 2cd36cb7
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:56:16 2011 +0200

    Show how to patch.

commit 8cd9ea9c
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:53:45 2011 +0200

    Allow options per patch.

commit 84fea623
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:48:47 2011 +0200

    Allow patching.

commit 8934eb92
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:30:46 2011 +0200

    Allow to keep directories in case of error.

    Default is to remove.

commit 74d0b2bd
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:24:49 2011 +0200

    Allow to have a=b=c, where a is key and b=c is value.

commit 034c2381
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:17:07 2011 +0200

    Another typo.

commit f5abcde0
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:15:44 2011 +0200

    Follow fixed typo.

commit 5b950e26
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:14:35 2011 +0200

    Extract does not need md5sum.

commit 6f725632
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:14:14 2011 +0200

    Pass md5sum directly.

commit 9f42d22a
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:13:53 2011 +0200

    Allow to pass empty md5sum.

commit c91fafb1
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:13:15 2011 +0200

    Fix typos.

commit 8919378d
Author: Łukasz Nowak <luke@nexedi.com>
Date:   Tue Sep 6 16:12:31 2011 +0200

    Fix examples.