Minor tweaks for property declaration style
Minor fixup in Foundation extension
Update code style rules on using dot syntax

Differentiate property access and getting
non-identical, generated values by not using dot
syntax for the latter methods.
Update code style to prefer initialize over dispatch_once

For implementation-level static vars, it's better
to not clutter the constructors.
Harden code by using copy properties where possible

http://bit.ly/1zEJN3W

Basically, copy properties are needed if the class
has a mutable subclass and the property should be
immutable.

Includes a minor fixup.
Merge pull request #31 from 3dna/peng/cleanup-6

Cleanup #6

Mostly refining code style and language usage.