Use the new <splashScreens> tag in bar descriptor.

This fixes the issue with splash images not appearing.
One or more images can be provided in Resources/blackberry
with the format: splash-<width>x<height>.<png|jpg>.
Example: splash-1200x700.png
Rename the default splash image using new filename format.
Merge pull request #21 from joshthecoder/TIMOB-12536

TIMOB-12536: Fixes splash screen images.