getVar update + Banned artist loli/shota fix + split method update

* Improved getVar's speed and allowed it to differentiate between a completely missing variable (returns undefined) and a variable with no value after the equal sign ("?tags=&page=1" returns "" for tags).
* Fixed the display of loli/shota post images from banned artists.
* Improved the speed of the split method on strings by providing a limit value of 1 for cases where only the first array value is desired.
* Other misc. optimizing/cleanup.