Squashed commit of the following:

Squashed commit of the following:

commit 394069a71fd5beb72e0033bfc3435b04734522bf
Merge: d53904d 0876f73
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Thu Apr 7 17:43:32 2016 +0200

    Merge branch 'inav-master' into servo-handling-refactoring

commit d53904d1dbe84143f92079c2c7b900197dd8d72d
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Thu Apr 7 11:41:45 2016 +0200

    Dualcopter and Bicopter presets removed since with new CUSTOM mixer they can be configured manually

commit 8e688bbf40a01cb28c7a25aca917c8e341031df1
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Thu Apr 7 10:02:09 2016 +0200

    Singlecopter removed

commit b8a3c0c9c87697ea4cc7109ce4d1c0d4ef3aefd5
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Thu Apr 7 09:37:18 2016 +0200

    MIXER_GIMBAL disabled, code removed as never really implemeneted

commit 834c0b2a66989ff8aead6b4d04f3cc54d86df95d
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Tue Apr 5 22:22:03 2016 +0200

    servo constraining

commit aad34473e0b3e14c595fdefc3bb17ca423dac654
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Tue Apr 5 22:15:29 2016 +0200

    further refactoring

commit b41b2019f1a45d802bc3aabb25fe3ff188259100
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Tue Apr 5 21:41:48 2016 +0200

    unneeded variable removed

commit c68a0a55eda66ae937c290aa80234e21f69022a6
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Tue Apr 5 21:14:15 2016 +0200

    MIXER_CUSTOM is now able of loading servo mixes as well

commit 6847354c2130e7459f2bf8e83ffee4690256cdb3
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Mon Apr 4 21:02:51 2016 +0200

    logic simplification

commit b7a6630e387c4be66b48eb9bda19e69ae75a95ec
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Mon Apr 4 20:34:38 2016 +0200

    unified way to write servos

commit 52eafa053c677db00900fe9fd3926941517c349c
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Mon Apr 4 14:22:23 2016 +0200

    more uncommon mixer presets removed on F1 targets

commit 5dd3dee9cfef83523e17e5a8d713ad688b3e974d
Author: Pawel Spychalski (DzikuVx) <pspychalski@gmail.com>
Date:   Sun Apr 3 15:39:10 2016 +0200

    exotic mixers disabled on F1 targets with fallback to QuadX