Update area stylization code

[waltweltonlair]

The existing code which applies area styles (in SE_AreaPositioning) has a number of bugs. It's also not documented very well.

I've gone through the code, and rewrote it for the most part. I also did extensive testing to verify the code is stable.

A number of bugs have been fixed:

• the code no longer hangs with area styles that have an angle
• negative repeats are correctly handled
• the generated symbol grid distribution now more closely matches the input feature geometry (fewer symbols are drawn overall)

[waltweltonlair]

Fixed with submission ​https://trac.osgeo.org/mapguide/changeset/3137.

[waltweltonlair]

Fixed in branch stream with submissions:

• ​https://trac.osgeo.org/mapguide/changeset/3140
• ​https://trac.osgeo.org/mapguide/changeset/3141