Revert "Fix vertical gesture touch calculations"

i can see the code isn't exactly clear in that regard - it seems like a
miscalculation but it was made to give items enough space to make an
easy flick possible. with a more correct approach it feels a lot harder
to just flick a "hide" because the space is so small, it'll more often
be a "slience" instead.

if you like we can look over the code together and implement a clean
implementation of that UI logic.

my g+ mail is drcmda at gmail.com you can add/contact me there if you
like.

This reverts commit 8cf0d5c62d5fa6c5e8fa51b8273893d32c5b787e.
FLAG_ACTIVITY_NEW_TASK re-added to floating windows

ActivityStack modified to not cancel results if window is floating and "new".

Change-Id: I45f3dcc816092daa4192be91828592a0b2b2ac59