Added redundant temp sensor
More redundant temp sensor changes. (After testing and debugging by reifsnderb)
faster GLCD (ST7920 SW-SPI) implementation / fixes

- fixed long menu entries (>14 or >18 chars) caused overrun in dogm lcd
implementation
- fixed pin set problem when in interrupt
- much faster ST7920 SW-SPI implementation
- increased ST7920 framebuffer size for more speed
Merge pull request #505 from MStohn/much-faster-glcd-st7920

faster GLCD (ST7920 SW-SPI) implementation / fixes
Merge branch 'reisnyderb' of https://github.com/ErikZalm/Marlin into Marlin_v1
Added servo actuated enstop coding to allow G28 command to engage and retract a servo to specified angles.
Missed some variable declarations
Integrated fixes from henrikbrixandersen pull request #504
Merge pull request #506 from codexmas/ServoEndstops

Servo Enstops working!