(#2460) - websql: update_seq should be an INTEGER

This fixes errors with the update_seq on
Android 2.x using the SQLite plugin, because we
need to know the type of the column in order to
bind it properly.
(#2492) - fast fail in travis

This will ensure that our "allowed failures" don't run
if any of the non-"allowed failures" fails.

So e.g. if PhantomJS fails, we won't bother running
the Safari/iPhone builds.
(#445) - Implement Incremental MD5 calculation

Replace jkmyers-md5 with Spark-MD5 in order to calculate MD5 hashes
incrementally. The use-case for this change is to avoid blocking the UI
thread when adding large attachments.