Patch fixes an issue with reading basedir on Windows. It fixes how
the code interprets opt_basedir on Windows by adding the correct
path separators and quotes for paths with spaces.

BUG#12664302 : mysql_plugin cannot recognize the plugin config file

Patch fixes an issue with reading a plugin config file. It adds
more information to the error messages to ensure the user is
using the options correctly. Also deals with paths with spacs on
Windows.