Merge branch 'release/0.2.5' into develop
(Pio::Mac) more YARD comments.
TODO Updated
Merge branch 'develop' of github.com:trema/pio into develop

Conflicts:
	pio.org
More YARD comments (Pio::Mac).
Add Pio::Mac#reserved?
Refactor Pio::Mac
Fix coding style of YARD examples.
Updated gem dependencies.
TODO Updated.
Version bump.
Merge branch 'release/0.2.6'