Merge pull request #194 from rudigens/master

Push latest changes.
Populate x&y pixel sizes in general block for roipac files.
Merge pull request #196 from khogenso/devel

Populate x&y pixel sizes in general block for roipac files.
Merge pull request #195 from rudigens/master

Updated file existence checks.
Couple of compile errors
Merge pull request #197 from khogenso/devel

Couple of compile errors
Merge pull request #28 from asfadmin/devel

Pull latest changes