Merge Doug's V13 of main plus lib changes

[nerdoug]

0.0.13 2020-06-02 DE: jump the Version number to sync up with master on Git

• 0.0.8 2020-05-29 DE: update my bot's calibraton data and correct printout
• add three methods to calculate tile angle:
• 1)non-DMP, using methods from 2 websites:
• https://github.com/jrowberg/i2cdevlib/blob/master/Arduino/MPU6050/examples/MPU6050_raw/MPU6050_raw.ino
• https://hester.mtholyoke.edu/idesign/SensorTilt.html
• 2)DMP, using one of the YPR values it provides, with a gimbal lock risk
• 3)DMP, using quaternions to rotate original "up" vector (0,0,1)
• -add a visible separator line of equal signs before each routine definition
• -add another debug print command: AMDP_PRINTF(x,y)
  • -left in the mpu.Calibrate... calls, although they're absent in Rowberg's latest demo code
  • -require the MPU6050 library with the fix on line 2764, by renaming it to MPU6050-fix2764.*. Had to change
  • MPU6050-6Axis_MotionApps_V6_12 as well, because it references MPU6050.h
  • -reformat #includes to clarify which libraries we created ourselves, and make lines < 140 characters
  • -remove all support for DMP interrupts, which latest Rowberg code doesn't need or use
  • -select DMP's YPR[2] as best tilt angle to use, in variable tilt, and trim code for other 2 methods

[nerdoug]

once again, lack of conflicts is strange, but I'm going for it, having lots of backups. Will need to review resulting code carefully.