AssetExtractor: Handle errors, skip directories

A repacked apk might contain subdirectory entries that are seen when
iterating through the ZipFile.  Ignore them instead of aborting
extraction.

Also, report AssetExtractor failures in the VPN log (previously only
reported in logcat).

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Bump version to 0.9 (901)

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
FeedbackFragment: Don't FC if there is no market:// URI handler

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>