Plane: releases notes for plane 3.9.0beta4

ArduPlane/release-notes.txt

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+Release 3.9.0beta4, 18th July 2018
+----------------------------------
+
+This is the fourth in a series of beta releases for plane 3.9.0. It is
+a major release, with a lot of changes.
+
+ - fixed compass detection on pixracer
+ - greatly improved OSD support
+ - fixed ARMING_REQUIRE=2 support (thanks Marco!)
+ - added automatic compass orientation support
+ - added probe for all external compasses on new ChibiOS boards
+ - fixed arming with compass disabled
+ - fixed flow control on F7 based boards
+ - fixed prealloc of DMA bouncebuffers
+ - added board specific builds for mRoX21 and Pixracer
+ - fixed mRoX21 IMU detection
+ 
+Many thanks to all who contributed to this release, and our beta testers!
+
+Release 3.9.0beta3, 11th July 2018
+----------------------------------
+
+This is the third in a series of beta releases for plane 3.9.0. It is
+a minor update to beta2
+
+Changes are:
+
+- fixed nul termination of system ID on ChibiOS
+- added PH4-mini support
+- fixed compass orientation on fmuv5
+- matched BRD_PWM_COUNT between px4-v3 and fmuv3
+- fixed MatekF405-Wing compass orientation
+- backup storage to microSD if possible
+
+
 Release 3.9.0beta2, 6th July 2018
 ---------------------------------