NLPAR with ROI

[saransh13]

If NLPAR is used with an ROI set, then the array indexing logic is broken. More specifically, out of bounds values are queried in multiple places. For specific input values, I was able to generate the errors in the following lines:

• negative index for exptIQ in Line 680
• negative record number for the temporary file, itmpexpt in Line 729
• negative pixcnt in Line 828