fixed bug in hstsim.py to ensure useFirstOrbit flag actually works

tweaked output naming for hstsim.py to allow for different setting combinations

added run_hst.py script

restructed repo and started hstsim.py, which basically works

Added back in correct saving of NIRSpec-G140 modes, which had accidentally been removed

Added warnings to obspar files, particularly to flag saturation

Explicitly added units for star radius, planet radius and transit duration for pandexo input dict

Added some more instrument info (eg subarray) to be written to obspar output files

Added indent to jwstsim.py where obspar file is saved

Merge branch 'master' of github.com:tomevans/pandexo_prep

Edited tepcat.py

Merge pull request #3 from AarynnCarter/patch-3

Add saving of observation parameters

Cosmetic edits to some print-out messages in jwstsim.py

Fixed some Python 2 and 3 compatability issues for urllib2 in tepcat.py