Update str_ireplace.js

After reading docs on formatting I decided to re-submit this replacement for str_ireplace().
This is a complete rewrite with all new code based on str_replace().
(str_replace() being a clean and efficient PHP 5.0 compliant substitute)

This proposed replacement is PHP 5.0 Compliant.

Original code does not allow for arrays, does not include optional 'count' and uses regex expressions which are unnecessary and waste of resources.
With all due respect to the original author.

Sorry for the re-submission but I thought you would like it re-submitted properly.
Glen
Update str_ireplace.js
Update str_ireplace.js
Merge pull request #157 from glenara/patch-6

Update str_ireplace.js