Added the "pattern_capture" token filter from Lucene 4.4

The XPatternCaptureGroupTokenFilter.java file can be removed once we
upgrade to Lucene 4.4.

This change required the addition of the commaDelimited flag to getAsArray()
to disable parsing strings as comma-delimited values.

Closes #3340
Merge pull request #3341 from clintongormley/pattern_capture

Added the "pattern_capture" token filter from Lucene 4.4