Adding '7-point' tower angle correction calibration

- adding Cn 5, 6 and 7

and getting rid off verbose level 3 and configuration_adv settings

- Making M665 compatible with repetier (see
http://reprap.org/wiki/G_code#M665:_Set_delta_configuration)

- M665 B also sets the radius for manual calibration menu

- Converting tower ajustment definitions to arrays - tower angle
corrections compatible with Esher 3D wizzard

- Only tower angles need to be adjustable with M665 and stored to EEPROM
- tower radius and diag rod can be adjusted in the FW only with #define

Refresh Marlin git helper scripts

- `mfadd` adds and fetches a user’s fork of Marlin
- `mfqp` invokes `git commit -m`, `mfrb`, `git push -f`

FLSUN and trailing whitespace cleanup

Add and apply interrupt helper macros

Cleanup after some direct commits

Fix double definition in configuration_store

https://github.com/MarlinFirmware/Marlin/commit/5e9726530f
ac1b9437c2

M43 Toggle & Z servo test - fix bug & add another check

Add Linear Advance values to EEPROM and LCD

Fix Makefile build

- use volatile for registers
- avoid implicit casts

Only queue babysteps if axis is in a known position

Identifed a display initialization issue.

This data corruption problem is very difficult.  Just changing the code
a little bit changes whether the problem even happens and what is
affected.  I need these changes in the main branch so I can operate with
the extra debug code always available and turned on.

Everything is setup such that if M100 is turned off or DEBUG(ECHO) is
turned off, the code is not affected.   M100 has been made a little bit
more inteligent so it can display the serial command buffers in a more
meaningful way (because the data corruption seems to often times end up
in that area).

Show Cancel/Continue screen for ABL "Level Bed"

Clean up endstop triggering code