Fix for MySQL version check subroutine (issue #7)

[arruor]

Adopting scop's idea for more reliable version recognition, both for local and remote servers.

Version check should work as follows:

• assuming that 32-bit version of MySQL is used by default
• check if 'version_compile_machine' ends with string '64' - if yes, then change version to 64-bit (on non-Windows OS)
• check if 'version_compile_os' ends with string '64' - if yes, then change version to 64-bit (on Windows OS)
• in all other cases MySQL version should be 32-bit

[major]

Sorry for the long delay in reviewing this PR. If you can update your patch to match trunk, I'll gladly merge it.