[Android] Fixed redundant touch moved events

Previously moving any finger would create `sf::Event::TouchMoved` events
for all fingers, even if their position didn't change at all.
Merge pull request #642 from MarioLiebisch/android-fingerfix

[Android] Fixed redundant touch moved events
[Android] Removed dependency on the window module from libsfml-main.a
[Android] Enable the usage of debug version of SFML libraries (#643)
[Android] Hide the status bar
[Android] Hide the navigation bar
[Android] Keep the screen turned on and bright
[Android] Workaround transparency issues on some Android devices
[Android] Avoid hardcoding the debug mode in AndroidManifest.xml
[Android] Updated target SDK version to 19
[Android] Fixed <uses-sdk> appears after <application> tag warning
[Android] Changed APP_PLATFORM value to android-9 in Application.mk
[Android] No longer force people to have debug version installed
[Android] Do not hardcode java const values (JNI)
Fixed typo in the sfml-graphics CMake file
Clarified Window::setIcon() ownership semantics
[Android] Rewrote key event handling

* This fixes duplicate TextEntered events and should properly handle
`AKEY_EVENT_ACTION_MULTIPLE` (including key down and key up events; as
far as possible; see comment). Unfortunately I don't have/know any IME
utilizing this, so can't test it.
* The back button is now mapped to the Escape key (best match without
adding new keys).
* The volume buttons are no longer intercepted by SFML and no longer
generate events.