GM teach-pendant support

New driver release: 1.1.1, 2013.11.16.
Add:    Teach pendant RS485 module support (both driver and doc)
Add:    Add errata to DOC
Modify: Send error msg and power fault, when any RS485 module disconnects (driver)
Fix:    Stepgen didn't allways stopped when power enable pin cleared during motion (driver)
Fix:    Start RS485 modules immediately after exported pins (there were a 6s delay in case of only input module was connected)
Fix:    Stepper config example, addf order was incorrect
Fix:    Small things in documentation

Signed-off-by: Bence Kovacs <bence.kovacs@generalmechatronics.com>