Minor refactoring:
moved frequent projection functions into the main class
added IDataSourceLayer interface
added exception class and messages
Rotation class refactored and extended with rotation around axis.
Projection arithmetics changed to float when in plane.
Projection limit tests checked and fixed.
Auto rotate and zoom implemented.
Auto rotate and zoom tests added.
Few old tests deleted.
Old tests deleted.
Old tests removed.
Auto zoom tests added for all projections.
Canvas bounds added, auto scaling fixed.
Implemented wrapper for memory resident metafile rendering.
Added PostScript writing support.
Unit converted moved into utility class.

File format tests added.