Optimize _clearCache().
It is cheaper to make an assignment or call strtolower() than to pluralize.
Merge pull request #2186 from bar/clearcache

Optimize _clearCache().
Revised CakePHP and external links on the home page
Some DocBlock improvements for Model.php
Merge pull request #2188 from ravage84/model-docblocks

Some DocBlock improvements for Model.php
Merge pull request #2189 from jameswatts/feature/home-links

Revised CakePHP and external links on the home page
Updated links to CakePHP resources
Merge pull request #2191 from jameswatts/feature/skel-links

Updated links to CakePHP resources
Added link to CakePHP roadmaps to support contributions
Added link to CakePHP roadmaps to support contributions