since password characters can contain quotes or spaces.

The proper quoting method for command line arguments used here was  extracted from
http://blogs.msdn.com/b/twistylittlepassagesallalike/archive/2011/04/23/everyone-quotes-arguments-the-wrong-way.aspx

Additionally, mysql_install_db.exe now passes root password to "mysqld.exe --bootstrap"
 in hexadecimal form, to handle potential special chars inside password string literal.

Added HeidiSQL as example, i.e cmake -DWITH_THIRD_PARTY=HeidiSQL  
and building MSI will bundle HeidiSQL.

- rename upgrade_wizard.exe to mysql_upgrade_wizard.exe
- have shortcut to upgrade wizard in the menu folder

If upgradable instances are found, bring a new dialog  to inform user about it. This gives user a
chance to deselect "database instance" feature early,  because experience shows nobody really looks at features and their in their description  in "customize setup" dialog. This also tells  user 
that existing instances can  be upgraded.

Allow MSI and  NSIS side-by-side installation if  installed NSIS package
differs in  "major.minor" version numbers. Still disallow MSI and NSIS 
if major.minor versions  of both packages match.

Problem: user without privileges can have an half-complete
installation, if he manages to click on "Ignore" for all  errors
in the installer. 

As a result, he will miss ARP registry keys, and uninstall 
will not be possible using  "Add/Remove Programs" applet.

The  general technique to generate MSI using CMake is taken from MySQL 5.5

Additional features not present in 5.5 installer : 
-optionally creating a new database
(as Windows service), using new mysql_install_db.exe to do the job
 
- optional upgrade of existing services from old MySQL or Maria installation.
This work is actually done by the upgrade wizard that is launched at the 
end of installation.