Update jquery.taghandler.js

if I type "postgressql" & in my avaliable list I have "PostgresSQL" (or type "java" vs "Java"), 
I want the autocomplete to add the latter.
I also added a foolproof behavior (that I got) where "PostgresSQL" is actually "PostgresSQL " 
int the available list (with a space)

another update : on top of the "ignorecase" feature, I added a feature like UpdateURL but 
"updateField" instead --> it is meant to automatically update an hidden field using the result 
of getSerializedTags()