Changes =~ to take a regular expression.

This change is a backward-compatible modification to make
=~ take an NSRegularExpression parameter instead of a String.

This is achieved by implementing __conversion on String.
Merge pull request #22 from nomothetis/regex-literal-convertible

Changes =~ to take regular expression.
Array.takeFirst
Array.indexOf with block
String.subscript, fixes #25
Array test case, list subscript
Xcode 6 Beta 5
Dictionary types updated (Beta 5)
New, improved, Array.flatten
Comments are now in reStructuredText format
Added count methods
Fixed a bug in XCTAssertEqualArrays
Readme
Renamed 'count' by 'countWhere'
Merge pull request #27 from jmnavarro/count_method

Added count methods
countWhere in readme