README: move maintainers into alphabetical order

also move those with merge rights to the top
fix link to merge rights
add to list of contributors
update how-to-get-involved

README.md

@@ -36,9 +36,12 @@
 
 - Developer chat: <https://gitter.im/ArduPilot/ardupilot>
 
-## Contributors ##
+## Top Contributors ##
 
-- [Github statistics](https://github.com/ArduPilot/ardupilot/graphs/contributors)
+- [Flight code contributors](https://github.com/ArduPilot/ardupilot/graphs/contributors)
+- [Wiki contributors](https://github.com/ArduPilot/ardupilot_wiki/graphs/contributors)
+- [Most active support forum users](https://discuss.ardupilot.org/u?order=post_count&period=quarterly)
+- [Partners who contribute financially](http://ardupilot.org/about/Partners)
 
 ## How To Get Involved ##
 
@@ -48,11 +51,11 @@
 
 - Desired Enhancements and Bugs can be posted to the [issues list](https://github.com/ArduPilot/ardupilot/issues).
 
-- Helping other users with log analysis on [http://discuss.ardupilot.org/](http://discuss.ardupilot.org/) is always appreciated:
+- Help other users with log analysis in the [support forums](http://discuss.ardupilot.org/)
 
-- There is a group of wiki editors as well in case documentation is your thing: <ardu-wiki-editors@googlegroups.com>
+- Improve the wiki and chat with other [wiki editors on Gitter](https://gitter.im/ArduPilot/ardupilot_wiki)
 
-- Developer discussions occur on <drones-discuss@google-groups.com>
+- Contact the developers on one of the [communication channels](http://ardupilot.org/copter/docs/common-contact-us.html)
 
 ## License ##
 
@@ -72,49 +75,50 @@ for reviewing patches on their specific area.  See also the list of developers w
 - [Andrew Tridgell](https://github.com/tridge):
   - ***Vehicle***: Plane, AntennaTracker
   - ***Board***: APM1, APM2, Pixhawk, Pixhawk2, PixRacer
-- [Randy Mackay](https://github.com/rmackay9):
-  - ***Vehicle***: Copter, Rover, AntennaTracker
+- [Francisco Ferreira](https://github.com/oxinarf):
+  - ***Bug Master***
 - [Grant Morphett](https://github.com/gmorph):
   - ***Vehicle***: Rover
-- [Tom Pittenger](https://github.com/magicrub):
-  - ***Vehicle***: Plane
-- [Chris Olson](https://github.com/ChristopherOlson) and [Bill Geyer](https://github.com/bnsgeyer):
-  - ***Vehicle***: TradHeli
-- [Paul Riseborough](https://github.com/priseborough):
-  - ***Subsystem***: AP_NavEKF2
-  - ***Subsystem***: AP_NavEKF3
+- [Jacob Walser](https://github.com/jaxxzer):
+  - ***Vehicle***: Sub
 - [Lucas De Marchi](https://github.com/lucasdemarchi):
   - ***Subsystem***: Linux
-- [Peter Barker](https://github.com/peterbarker):
-  - ***Subsystem***: DataFlash
-  - ***Subsystem***: Tools
 - [Michael du Breuil](https://github.com/WickedShell):
-  - ***Subsystem***: SMBus Batteries
   - ***Subsystem***: GPS
-- [Francisco Ferreira](https://github.com/oxinarf):
-  - ***Bug Master***
-- [Matthias Badaire](https://github.com/badzz):
-  - ***Subsystem***: FRSky
+  - ***Subsystem***: SMBus Batteries
+- [Peter Barker](https://github.com/peterbarker):
+  - ***Subsystem***: DataFlash, Tools
+- [Randy Mackay](https://github.com/rmackay9):
+  - ***Vehicle***: Copter, Rover, AntennaTracker
+- [Tom Pittenger](https://github.com/magicrub):
+  - ***Vehicle***: Plane
+- [Bill Geyer](https://github.com/bnsgeyer):
+  - ***Vehicle***: TradHeli
+- [Chris Olson](https://github.com/ChristopherOlson):
+  - ***Vehicle***: TradHeli
+- [Emile Castelnuovo](https://github.com/emilecastelnuovo):
+  - ***Board***: VRBrain
 - [Eugene Shamaev](https://github.com/EShamaev):
   - ***Subsystem***: CAN bus
   - ***Subsystem***: UAVCAN
-- [Víctor Mayoral Vilches](https://github.com/vmayoral):
-  - ***Board***: PXF, Erle-Brain 2, PXFmini
-- [Mirko Denecke](https://github.com/mirkix):
-  - ***Board***: BBBmini, BeagleBone Blue, PocketPilot
 - [Georgii Staroselskii](https://github.com/staroselskii):
   - ***Board***: NavIO
-- [Emile Castelnuovo](https://github.com/emilecastelnuovo):
-  - ***Board***: VRBrain
+- [Gustavo José de Sousa](https://github.com/guludo):
+  - ***Subsystem***: Build system
 - [Julien Beraud](https://github.com/jberaud):
   - ***Board***: Bebop & Bebop 2
+- [Leonard Hall](https://github.com/lthall):
+  - ***Subsystem***: Copter attitude control and navigation
 - [Matt Lawrence](https://github.com/Pedals2Paddles):
   - ***Vehicle***: 3DR Solo & Solo based vehicles
-- [Gustavo José de Sousa](https://github.com/guludo):
-  - ***Subsystem***: Build system
-- [Jacob Walser](https://github.com/jaxxzer):
-  - ***Vehicle***: Sub
+- [Matthias Badaire](https://github.com/badzz):
+  - ***Subsystem***: FRSky
+- [Mirko Denecke](https://github.com/mirkix):
+  - ***Board***: BBBmini, BeagleBone Blue, PocketPilot
+- [Paul Riseborough](https://github.com/priseborough):
+  - ***Subsystem***: AP_NavEKF2
+  - ***Subsystem***: AP_NavEKF3
 - [Pierre Kancir](https://github.com/khancyr):
   - ***Subsystem***: Copter SITL, Rover SITL
-- [Leonard Hall](https://github.com/lthall):
-  - ***Subsystem***: Copter attitude control and navigation
+- [Víctor Mayoral Vilches](https://github.com/vmayoral):
+  - ***Board***: PXF, Erle-Brain 2, PXFmini