migrate TODOs to the issue tracker
update to SQLCipher for Android 3.0.2

fixes #3123
refs #2884
hook up the KDF iteration calibrator

refs #2252
move SerializedSecretsX dependency to app layer

versioning of serialized secrets doesn't belong in the crypto layer
implement versioned loading and migration for SS

refs #2252
use configurable KDF itercount in Serialized Secrets

refs #2252

at this stage however the value is still fixed at 100
add PBKDF2 calibration settings

refs #2252
install KDF calibrator

refs #2252

we calibrate the KDF (1) on every encryptAndSave() and
(2) at fetch time if the iteration count is too low.
update tests after KDF calibrator installation

refs #2252
advise use of a thread in the documentation

refs #2252
suppress several harmless lint warnings
test version 0 -> version SS migration