Fitting ma_control_file_test into the mytap unittest framework:
new directories:
- unittest/storage/ for unit tests of any storage engine
- unittest/storage/maria for ... Maria, containing ma_control_file-t.
Later, older tests like ma_test*, ma_test_all (but which is Unix
dependent in its current form) could move here too.
The plugins macro enable building of unittest/storage/X for any
enabled engine X which has such a directory.
If Falcon wants to have unit tests there too, I may have to merge
this patch into 5.x one day.


config/ac-macros/plugins.m4:
  If a storage engine has a directory in unittest/storage, build this
  directory.
configure.in:
  build storage engines' unit tests.
storage/maria/Makefile.am:
  ma_control_file_test moves to unittest/storage/maria
storage/maria/ma_control_file.c:
  more error codes when opening the control file fails.
  ma_control_file_end() may now return an error if my_close() failed.
storage/maria/ma_control_file.h:
  more error codes when opening the control file fails.
unittest/Makefile.am:
  adding unit tests for storage engines.
  Note that unit.pl simply recurses into "storage", so if a unit test for
  storage engine X has been built previously, and now you re-configure
  (without making clean) to disable this engine, then the unit test of
  X will not be rebuilt but will still be present in storage/X, so will
  be run.
unittest/storage/maria/ma_control_file-t.c:
  Making the test fit the mytap framework (return all the way up
  the stack instead of assert(); use the mytap functions plan(), ok() etc).
  Adding test of file too short/long.
unittest/storage/maria/Makefile.am:
  a_control_file-t is added to the Maria unit tests.
  Later, older tests (ma_test1 etc) could also move here.
unittest/storage/Makefile.am:
  New BitKeeper file ``unittest/storage/Makefile.am''