Fix spelling error.
Remove trailing whitespace.
More spelling fixes.
Add requirements regarding case-sensitivity.
Merge pull request #216 from Crell/psr-4-case-folding

Psr 4 case folding
Fix a wrong comma
Merge pull request #217 from leofeyer/patch-1

Fix a wrong comma in the PSR-4 file
Merge branch 'master' of github.com:php-fig/fig-standards
reorganize and add case rules, renumber bullets