Minor tweaks to readme.
Edits to is_blank() method
Fix bug which left SExtractor assoc file off of list of temporary files to delete.
Fix bug: make path to SCAMP head file explicit.
Fixed bug in naming of SCAMP head file
Code to extract and log SExtractor version
Add line with IQMon version to log file
Added version info for SCAMP and SWarp to log
Added astrometry.net output to log
Update IQMon.__version__ to 1.3.3 and update read me with v1.3.3 info.
Merge branch 'develop'