Switch to char[] for data storage in-memory.

This change uses getBlob/setBlob to store byte[]-encoded char[]s in the
database, rather than getString/setString. It also tries its best to
destroy in-memory copies of things when fragments are stopped, etc.

HOWEVER, IT BREAKS SUBSTRING SEARCH FOR UNICODE SUBSTRINGS. That worked
before--I'm not sure why this breaks it, but it may be an encoding
incompatibility.
Autoformat.
Updated comment.
Fix bugs in char[] conversion.

1. Don't append null chars from char[] buf to TextViews.
2. Do zeroing out of in-memory copies on onDestroyView, not onStop.
Merge branch 'master' of github.com:danmarg/sesame