kEpsilon was added to avoid the loss of precision.

From pull #73, contributed by Alexander Alekseev.
Increased performance. Replaced iterator++ with ++iterator.

From pull #73, contributed by Alexander Alekseev.
Geometry functions added.

Inspired by NSGeometry by Apple. Also changed _centerOfPolygon method.
It is smaller and (maybe)
faster now.

From pull #73, contributed by Alexander Alekseev.
Some optimizations.

From pull #73, contributed by Alexander Alekseev.
New geometry and optimizations.

From pull #73, contributed by Alexander Alekseev.
New geometry functions.

MakeVector was added.
Comments for geometry functions were added.
From pull #73, contributed by Alexander Alekseev.
New functions + code optimization.

Functions DGMakeCursorData, DGMakeGlyph, DGMakeLogData,
setValuesInLookUpTable were added.
Code optimization.
From pull #73, contributed by Alexander Alekseev.
Minor fixes.

From pull #73, contributed by Alexander Alekseev.