Fixes #3932

 * you can now write browserCode==ff;referrerKeyword!= to select all visitors using firefox and that have a keyword set
 * or you can write referrerKeyword==;browserCode==ff to select all visitors using firefox and that did not have any keyword set
Also fixes #3933

Refs #2135
 * fixing last bugs with segment selector encoding (working on chrome + FF + opera) - I 'hope' it will work on iE...