Refactored the test case: hardened and extended it. Created test inc file
to abstract the task of relocating binlogs.

Also, disabled it on windows for not cluttering the test case any further, 
as it depends heavily on doing filesystem operations and path handling.

mysql-test/include/relocate_binlogs.inc:
  Auxiliar include file that performs the relocation of binary logs
  listed in an index file.