Bugfix - Doc-block cleanup

This PR cleans up some more code comment documentation (phpDoc), modernizing the style used in the project.

As part of this process, the following doc-blocks have been removed as they're unnecessary and redundant in PHP 5:

- `@abstract`
- `@access`
- `@final`
- `@package`
- `@static`
- `@uses`

This PR also converts the `@const` and `@var` tags over to the new, preferred `@type` tag.

Finally, the file header has been updated to match the readme.