Merge branch 'feature-loadingscreen' into 'devel'

android/assets/gfx/bar_background.png

android/assets/gfx/bar_foreground.png

android/assets/gfx/launch_cs.png

android/assets/gfx/launch_de.png

android/assets/gfx/launch_sk.png

android/assets/gfx/lines_cs.png

android/assets/gfx/lines_de.png

android/assets/gfx/lines_sk.png

core/src/cz/nic/tablexia/Tablexia.java

core/src/cz/nic/tablexia/loader/zip/ZipAssetLoader.java

core/src/cz/nic/tablexia/screen/gamemenu/GameMenuScreen.java

core/src/cz/nic/tablexia/screen/loader/LoaderAssets.java

core/src/cz/nic/tablexia/screen/loader/LoaderScreen.java

core/src/cz/nic/tablexia/screen/loader/LoadingBar.java

...z/nic/tablexia/screen/loader/event/FileDownloadEvent.java

...z/nic/tablexia/screen/loader/event/LoadingStatusText.java