Move installation instructions at the top of the README

Change PHPDoc return type of values() (myclabs#37)

To improve IDE autocompletion on the resulting items when iterating

Merge pull request myclabs#21 from lorenzomar/master

Change calls to method toArray() from self::toArray() to static::toArray()

Merge pull request myclabs#19 from chriseskow/values

Add static values() method to return array of all Enum instances (fixes myclabs#18)

Merge pull request myclabs#14 from mirfilip/hotfix/search-type-safe

Fix for search() is not type safe. Fixes myclabs#13

Merge pull request myclabs#11 from drealecs/performance-optimizations

some performance improvements

Improved documentation

Merge pull request myclabs#2 from garoevans/patch-1

Add caching to `toArray` method

Moved to MyCLabs