ANSEL and CMCON are only required for a 12f675 that has analog input capability. A12f629 does not have analog inputs so these commands are not required for the 12f629.
The clear command is not required and the variable "I" is also not needed as there are no for/ next loops in the program. A While 1 / wend forms a continuous forever loop so the goto command after the wend is not required. The pause 19 is in the loop so that the pulses are send every 19 milliseconds which is the repeat rate required by the servo decoder.