Implement check for tabs in config-file. Fixes resets.

This commit creates a fail-fast exception-throwing guard inside the
method for handling config-reloading in the main plugin class.

If a config-file contains a tab, an exception will be thrown when
the plugin loads (as it did before), which means the plugin will not
load correctly. However, upon reloading with the reload command, an
exception is thrown before the current settings are overwritten.

This fixes a long-standing issue with config-files resetting upon
reload with invalid syntax. Verification is needed, as this commit
has only been tested on OS X where tabs and carriage returns are
injected via vim.
Merge branch 'bleeding' of github.com:garbagemule/MobArena into bleeding