Appending XAJAX Functions Performance

Increase performance by not calling array_push() every time. array_push
is recommended for pushing multiple values in one function call. After
performing a few tests,, this is only good when you are pushing >= 30
values, otherwise $array[] = 'value'; is best, it takes 1/2 the time of
calling array_push().
Merge pull request #52 from Akshay2598/master

XAJAX Performance enhancements.