Revert "Upgrade jQuery to 1.11"

This reverts commit c04bfee4bfce8aa1f81aa7bbb532527d804c4fff.

It seems jQuery 1.11 causes some trouble in browser detection.
It throws similar errors in the whole Praktomat system, as seen in the image below.

I know this is just a quick workaround, but without it the Praktomat will not work.


![jquery2](https://f.cloud.github.com/assets/1014402/2282819/f5d97532-9fb3-11e3-843f-c15cd23314fb.png)