+sharedInstance is rewritten to support multiple subclassing. instancetype keyword is used by default now.
Description is completely rewritten via AppleDoc notation, methods are regrouped.
Docset for Xcode target is added to build docset via appledoc if it is in system.
REAMDE.md is updated.
Squashed 'VRAppSettingsExample/Requirements/VRFoundationToolkit/' changes from 593add1..8f1012f

8f1012f README is updated.
e63865b VRFoundationToolkitOSX target is added to project, to compile under OS X. Type is casted in -md5 to eliminate warning.

git-subtree-dir: VRAppSettingsExample/Requirements/VRFoundationToolkit
git-subtree-split: 8f1012f02e448b4b6d5b55911f779690736723c2
Merge commit '71ba6716f46f14d651d019839217d79617484fd9'