4/4 Commit - License

- Added license file and reference in all code pages.
- Added annotation constants.
- Added tag/point exceptions.
- Modified SprPoint3D structure to include a DrPointDbl com reference.
- Added placement condition to SprTag, and revised the template dictionary.
- Added various properties to SprTag.
- Created methods for reading/writing tag default values into the registry.
- Made SprApplication inherit iDisposable, and created dispose and deconstruct methods.
- Optimized point selection methods.
- Rewrote tag placement and leader edit methods.
- Created a threadpool callable tag_update method.