update koreader-base
use koreader/koreader travis icon and link
need ndk-build command in PATH to build koreader for Android
Merge pull request #606 from chrox/master

finally fix travis build of koreader
refactor: update reader to use new launcher
Merge pull request #607 from houqp/houqp-master

refactor: update reader to use new launcher
Claim that Android devices do not have a keyboard

For now, we can probably live better with the assumption that
Android devices do not have keyboards. That should be replaced
by an actual check, though.
Merge pull request #610 from hwhw/master

Claim that Android devices do not have a keyboard
update ignore file
add missing Blitbuffer since it's removed from global space
detect screen DPI for android devices
remove least used koptoptions to save space for small screens
GUI tweaks for small screen
that sets a maximum size that won't render content outside of the screen
use android config interface to detect device keyboard and screen dpi
Merge pull request #611 from chrox/master

use android config interface to detect device keyboard and screen dpi
Android: use FFI-based dlopen() and JNI interfacing
Merge pull request #613 from hwhw/master

Android: use FFI-based dlopen() and JNI interfacing
fix FC in Android 2.3 when calling util.realpath
fix blank screen on Android 2.3
Now blitbuffer is initialized with android.screen field
which is possible to grab before native activity window is inited.
Merge pull request #615 from chrox/master

fix blank screen on Android 2.3