use the PSIMAGE_SET_NUMCOLS, etc macros

[eugene]

I have fixed a few examples of code that looks like this:

*(psMathType*)&out->type = image->type;
*(psS32*)&out->numCols = numCols;
*(psS32*)&out->numRows = numRows;

to use the macros defined for this purpose:

P_PSIMAGE_SET_TYPE(out, image->type);
P_PSIMAGE_SET_NUMCOLS(out, numCols);
P_PSIMAGE_SET_NUMROWS(out, numRows);

This operation overrides a 'const' element in a structure.

The danger of the first version, aside from being generally difficult code to
parse, is that the behavior depends on having the correct type set. If the type
is changed, or put in wrong, errors will occur.

I have fixed examples in:

psImageStructManip.c:111-113
psImageStructManip.c:357,358
psImage.c:

(also note that the col0,row0 elements do not need to be modified in this way
since they are not 'const').

[eugene]

I just discovered that the macro P_PSIMAGE_SET_NUMROWS had an error and was
setting the number of columns instead. Since it was not actually being used,
this didn't actually cause any problems, but still fairly worrisome...

[Paul Price]

Fixed by EAM.