ESC speed control

Remove the low pass filter on the ESC, allowing higher P(proportional) control values, which stabilizes the quad in wind gusts.
 * http://www.diydrones.com/profiles/blogs/zippy-ac2-with-low-pass-filter-removed-from-escs
 * https://github.com/sim-/tgy
 * http://www.rcgroups.com/forums/showthread.php?t=1513678 ESC firmware flashing
 * http://diydrones.com/profiles/blogs/autoquad-esc32-v1r5
 * http://diydrones.com/forum/topics/flashing-3dr-escs-or-rc-timer-escs-with-much-better-firmware?commentId=705844%3AComment%3A853374

http://code.google.com/p/autoquad/wiki/esc_common Standard ESC not meant for quad control but for aircraft.

http://wiki.openpilot.org/display/Doc/Flashing+Instructions

http://www.rcgroups.com/forums/showthread.php?t=1513678

bldc
https://open-bldc.org/wiki/Open-BLDC