add launch commmand, remove doc on start & reset

- launch command defaults to the old reset functionality
- launch --no-reset is the old start functionality
- start and reset are still implemented as is, but not documented

atmel start and reset both start the device only start calls a jump
instead of resetting the device (which can lead to problems with bugs
associated with initial device state not matching datasheet or device
state after normal reset).  this update combines these two commands
because they essentially do the same activity, only the approach is
different.

no functional change here, only labels / commands have changed
add debug strs, comments, move fcn desc, whitesp

- add several debug strings for various errors
- add function comments
- move function descriptions to headers files and prototype section
- add fixme marks to fcns where broken
- join fcn start braket with header to improve folding
- add summary of atmel commands
- add macro for ATMEL_BLOCK_SIZE