DEBUG: debug statements for Courier
Fix misleading run-time statements. Calibration doesn't take 30 seconds.
README: explain how to use background services with CW
readme: add table of contents for readability
readme: document new detach/reattach functions
tests: add SQLCipherOpenHelperTest

It also handily tests our callbacks!
pass char[] to SQLCipher instead of String. fixes #2253
Merge branch 'master' of https://github.com/guardianproject/cacheword into deinitialize