Update Gradle, Temp Support Library Issue Fix

Support Library r20 seems to conflict with libraries built with r19.1.
Manually using r19.1's library until effected libraries are rebuilt with
r20
Fix spoiler tag rendering, other small tweaks

GFAQs switched from using spans for spoilers to 
 tags in the html,
adjusted to match. Moved spoiler and quote tag constants into variables
for easy future changing.
Remove excess ad element when not logged in
Apparently "apply plugin: 'android'" is deprecated
Syntax & method order tweaks
Renamed methods, new post timeout dialog
Allow manually setting last path and desc
Touch up the post timeout dialog
Version 2.1
Merge remote-tracking branch 'origin/dev'