Exclude patterns for VCS directories are incorrect

The regexp used for excluding vcs directories aren't correct for code_sniffer.

On coder_sniffer/Drupal/ruleset.xml we use the following pattern:
<exclude-pattern>*/.hg/*</exclude-pattern>

sadly, one internal project is know as "lhg" and so match the exclude pattern because dot is a wildcard.

I advice to escape this so dot can be only a dot when excluding patterns.

I have attached the patch to fix this issue.