check window stack before sending events
This should fix FC on Android with "Start with last opened file" checked
fix cannot load thrift library on Android
update luajit-launcher
fix two finger pan gestures detection
This is a stupid bug I introduced when I thought 0 evaluated to be false.
Actually in Lua only explicit `false` and `nil` are evaluated to `false`
all other values are true in logical expressions.

This should also fix #546. Probably because the touch screens in Kindle
are not as sensitive as in Kobo, this problem is not discovered early
util I play with multi-touch on a Android phone which has a sensitive
enough screen to expose this bug.
Merge pull request #633 from chrox/master

fix two finger pan gestures detection
use checked/unchecked for hightlight drawer style
add night mode option that inverts screen color
use checked/unchecked for show page overlap option
decrease toc entry indentation
use checked/unchecked for zooming options
decrease indentation of touch menu entries
use checked/unchecked for language option
update pot file
respond Menu key to show reader menu
save doc settings when receiving IntoSS or Suspend or SaveState events
add tap zone configuration for the minibar
fix typo
fix insensitive rotate gesture detection
This should fix #546.
strip encoding suffix in locale name like zh_CN.utf8
So that we can automatically change to language defined in
the LANGUAGE or LANG env variable.
automatically set language on Android