Visual Studio builds each configuration in a different sub-directory.  Only the sub-
directories for release and debug are currently searched.


mysql-test/lib/mtr_misc.pl:
  Bug#23865 mysql-test-run.pl on Windows only supports debug and release configurations
  - Added usage comments.
mysql-test/mysql-test-run.pl:
  Bug#23865 mysql-test-run.pl on Windows only supports debug and release configurations
  - Moved Initial_Setup function to the command_line_setup function.
  - Defined new argument vs-config which can be used to inidicate the VS Configuration
  used to create the test executables. Argument can also be controlled with
  MTR_VS_CONFIG environment variable.