Update SolrSearch_Helpers_Facet.php

The value might contain additional characters not matched by \w such as parentheses or others. I don't see any problem in matching anything but a " as that would be the following character anyway. I have made this modification in my installation and it seems to work fine.
Merge pull request #109 from marcobat/patch-4

Update SolrSearch_Helpers_Facet.php
Updated version to 2.1.1.
Merge branch 'release/2.1.1'
Merge tag '2.1.1' into develop

Release fix for #112.