jquery.client: Recognize IE12 correctly

IE12's User-Agent is, unhelpfully:

Mozilla/5.0 (Windows NT 6.4; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36 Edge/12.0

Unsurprisingly, this is currently recognized as Chrome 36.
The word "Trident" also doesn't appear any more, because IE12's
new layout engine is called "Edge". So look for that string instead.

Change-Id: I94a4ff2cc37ae6ce0c677ef92eeb6a2dff30c1f4
Merge "jquery.client: Recognize IE12 correctly"