add more constants to exitcodes.py
convert to using salt defined exit codes
use salt exit codes
use salt exit codes
use salt defined exit codes
use salt defined exit codes.
use salt exitcodes everywhere.
make sure to import salt.exitcodes
revert changes to shim.

The shim can't have any external dependencies.
Correct comment. Keep in sync with exitcodes.py
Merge pull request #18897 from UtahDave/2014.7local

Use Salt defined exit codes.