Set player activity as single instance

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Refactor crossfade support into a separate class

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Restore playlist scroll position on player return

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
[JNI] Prevent crash on unitialized objects

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Prevent crash with ill-formed playlist file entries

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Check for Bluetooth connection receiver before unregistering

Apparently the Z933 (glaucus) crashes if we don't add this check.

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>
Prevent crash caused by null queue on phone state change

Signed-off-by: Claudio Matsuoka <cmatsuoka@gmail.com>