OTP code fixes -  implement -k code.   ( WIP )
OTP code fixes -  implement -k code - Done, and working, and tested.
px_uploader.py to support v4 protocol with OTP.
WIP fix for MO?
px_uploader.py to support v4 protocol with OTP.
handy to have the bl_upate command in the 'auth' build.
make rev4 px_uploader.py backward compatible with rev3 boards and earlier.   ( without this it gives a timeout on rev3 bootloaders )
bugfix in auth.c for the -m command not working reliably.
Merge branch 'auth' of https://github.com/PX4/Firmware into auth
bring the makefile for minimal 'auth' v1 build up to speed after the merge.  ( bringing tweaks from the v1 default buld across)
create makefile for minimal 'auth' v2 build  after the v2 merge.   - needs libtomcrypt
fix paths in 'auth' 's usage output.
remove some obvious unneeded crud from the "minimal" auth build.    more can go, but this is a start.
This frees enough ram that the 'auth' command no longer reports out of memory errors when run.
the "rgbled rgb X X X" command was broken, and would set green when you asked for red, and blue when you asked for green, and never set red.   - off by 1 error in parameter numbering.
Implement three new parameters/options for the auth command. - support reading/writing serial data from SD, and reading/writing OTP/s to SD.
* also re-factored code to clean it up and make it clearer what its doing.
* renamed a few veriables that were a poor choice ( like 'err', verifycert, and lockcert )
* made it much more explicit where serial and OTP are being loaded from.
* added function prototypes to reduce number of warnings this code generates.
* etc.
added a second public key to the "verify" step, to allow verifying against 3DR's public key as well as buzz's test key.
Merge pull request #377 from davidbuzz/auth

Auth library updates