Dev: Restore jQuery 1.11.1 - was removed by mistake in a previous commit
Fix: Remove redundant code from the column visiblity method

* This fixes DataTables/DataTables #340
Docs: Improve the documentation of smart filtering in DataTables

* Explain what smart filtering is
* How it can effect passed in regular expressions
* Improve column().search() examples to show one with smart filtering
  and one with exact matching.
* API examples updated to match the examples given in the documentation
* This fixes DataTables/DataTables #344