libgps: update all the things

 * Update agpsril ni_message to send HMAC instead of length
   (according to the stock framework)

 * Remove cm_ prefixes

 * Renaming stuff

 * Add enter/exit debug statements

Change-Id: Id2a11455bcd0c0d7a53385bfa008835f4c2c7618
Signed-off-by: travp624 <travp624@gmail.com>