Fix: query.engine can be 'MySQLdb' for msyql.

query.engine could be 'mysql' or 'MySQLdb' for mysql driver.
Remove dependency on jquery-cookie plugin

Replace plugin with simpler get and set methods.
Merge pull request #530 from djfarrelly/master

Remove dependency on jquery-cookie plugin
Merge pull request #513 from ifduyue/fix-ifequal-mysql-engine

Fix: query.engine can be 'MySQLdb' for msyql.