Mantid return codes

[peterfpeterson]

Currently mantid always returns 0 on exit. Change it so when something goes wrong it gives a different return code. A specific example is a python script which should never work under any conditions (fail.py):

#!python
blah

Executing this (in linux) and printing the result gives

MantidPlot -xq fail.py ; echo $?
ConfigService-[Information] This is Mantid version 3.0.20140108.1658 revision g5a8aa54
ConfigService-[Information] Properties file(s) loaded: /home/pf9/builds/mantid-release/bin/Mantid.properties, /home/pf9/.mantid/Mantid.user.properties
ConfigService-[Information] Logging to: /home/pf9/.mantid/mantid.log
FrameworkManager-[Notice] Welcome to Mantid version 3.0.20140108.1658 - Manipulation and Analysis Toolkit for Instrument Data
FrameworkManager-[Notice] Please cite Mantid in your publications using: http://dx.doi.org/10.5286/Software/Mantid
ConfigService-[Information] ParaView is available
MantidUI-[Notice] MantidPlot is shutting down...
0

which gives no indication that a failure happened. Running this same script through the python interpreter gives

python fail.py ; echo $?
Traceback (most recent call last):
  File "fail.py", line 1, in `<module>`
    blah
NameError: name 'blah' is not defined
1

Similarly a script (pass.py) should return 0:

#!python
import sys
sys.exit(0)

This ticket is to give more meaningful failure feedback when using the "-xq" flag on the command line.

[peterfpeterson]

This issue was originally trac ticket 8686