Committing bug fixes in MooseLauncher, JobLauncher, and
JobLauncherAction related to local job launches. This fixes the
following: 
1. Local yaml generation on Mac (launch script changed to use '\n'
instead of ';')
2. Needed files not pushed to temp working directory for local launch.
3. Generated files not being pulled back from temp working directory on
local launch.
4. Launching moose job with an input file given as an absolute path
crashes moose, and is not needed since we are in the temp working dir.
It now just launches /path/to/mooseapp -i input.i
5. Problem where local download directory was not being set correctly if
no input file was specified, as in the case with yaml generation.

Tested all of this locally and remotely on Mac, Linux, and Linux VM. 

Signed-off-by: Alex McCaskey <amccaskey2223@gmail.com>