unpackFrame_ROIPAC_raw.py fixes

[bjmarfito]

• Use default values instead of using DOPIQ when focusing images
• Use os.path.abspath for the image name so stackStripMap.py can read the path of the raw files when processing
• Change the file format to UNIX using :set ff=unix

[hfattahi]

@bjmarfito was there a reason that you remove the Doppler estimation here?
I doubt if there are Roi_pac users. Not possible for me to test right now. Can you confirm if you have tested and with what kind of data?

[bjmarfito]

Hi @hfattahi , I used the unpackFrame_ROIPAC_raw.py to process ROIPAC formatted JERS data. I used the default doppler estimation for JERS data and it worked correctly. I actually can't remember the reason why I removed the DOPIQ since it was many months ago after I submitted this PR. Though, I already brought it back for users who need it and added an argument to either use DEFAULT of DOPIQ for doppler estimation.