Merge pull request #627 from houqp/houqp-master

fix(setting): handle empty setting files properly
adapt reader footer for small screen
adapt touch menu for small screen
strings not shown on GUI will not be translated
This may encourage users in transifex to join Koreader project.
add option to load last opened file automatically
adjust option orders in readermenu
fix license version in reader usage
add previous and next chevron icon in touch menu
add Korean in language table
now make po should be issued manually
Merge pull request #629 from chrox/master

GUI adaptation for smaller screens
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