bootanim: Add continuous splash support

 * We may or may not want to have a very smooth transition from the
   bootloader into Android by way of a continuous splash feature.
 * Add a compile-time flag which disables the initial screen clearing
   so that we don't drop a frame during the transition.

Change-Id: Ic453c901f1030ffebd9bdbeec59109bb5c585629
core: Add support for Luxembourgish

Change-Id: Idd65417a08c5035a75e0d33617dc28c88757a293