Use variable for maximum number of suggestions for quicksearch.
And hide suggestions when search field is emptied, or when no suggestion are found.

We removed them because of FS#2447 a while ago. But as the original
problem was most probably only caused by the gradient for the page
background and that's using a PNG now, the gradients for the buttons
should be fine. Please test to double check if this change causes
performance problems in Firefox.

reduce the content region width on auth forms (profile, login, register & resend password) to match the fieldset

When the search input is still only a few characters, the number of matching pages is big.
Browsers have heavy work to progress this whole return, better cut off so only the part that is directly displayed will be sent.

This should make migrating from MediaWiki a bit easier.

this will be removed soon again. plugins using jQuery should make sure
they are compatible to jQuery 1.9

This reverts commit f2cb3ec7.

Turns out I was too fast merging this. I can't get PHP's bzip handler to
handle a bzip1 compressed file.

in fact .tbz is tar.bz (bzip1) and .tbz2 is what tar.bz2 is used
commonly.