Doc: Fixed footer style and information for offline builds.

-footer is left aligned and smaller text.
-footer contains fewer <div> which were not used.
-CSS rules for footer changed to accommodate new specifications.
-information not relevant in offline builds taken out.

Task-number: QTBUG-33802
Change-Id: Icc57bad9ead8ce812d5df8e72a7bac8c22831b5f
Reviewed-by: Sami Makkonen <sami.makkonen@digia.com>
Reviewed-by: hjk <hjk121@nokiamail.com>
Remove unused field.

Fix crash on Android 4.4

Change-Id: Ibee584c0154b0b116af58477302e7e8385f0290d
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Android: implement a simple cache mechanism for assets dirs.

AAssetManager_openDir is a pretty slow operation, so we are caching the most used dir contents.

Task-number: QTBUG-34464

Change-Id: If198f7dae0d6961291c992e6eb46839ba5455819
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Android: Avoid re-creating Random objects.

We where re-creating a Java Random object each time the seed was set,
this causes unnecessary overhead as the old objects becomes  subject
for garbage collection.

Change-Id: I7aa48f5380f86d6c0d57eaeadc71b9b2b146034d
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Android: Check for null pointer before calling ANativeWindow_release()

Calling ANativeWindow_release() with a null pointer will cause
a SIGSEGV.

Task-number: QTBUG-33955
Change-Id: If7d1afa3baea04360507eec5042b4e18a0272527
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>