Added Set struct + tests
merge master from upstream
Merge branch 'master' of https://github.com/maxpow4h/swiftz
Added minus,intersect and Printable + tests
Added more set operations + overloaded operators.
Added working, but ugly, List
List now implements ArrayLiteralConvertible
List now has Functor instance and some more conveniences
added safeHead and safeTail to List
added test for List Functor
moved Box to Box.swift, renamed safeHead to head
List implements Sequence
Merge branch 'master' of git://github.com/tLewisII/swiftz

Conflicts:
	swiftz.xcodeproj/project.pbxproj
Added any? and Set() to Set
Merge branch 'list' of git://github.com/cobbal/swiftz

Conflicts:
	swiftz.xcodeproj/project.pbxproj
	swiftzTests/swiftzTests.swift
Array map tweaks
added NonEmptyList with a functor
malloc replaced with UnsafePointer.alloc

free replaced with UnsafePointer($0).destroy()