Revert "Merge pull request #43 from soundcloud/master"

This reverts commit 746cc56c8b8c46e06a9d46be5141834013082602, reversing
changes made to 4b0b3bf796e84fe99467b592372dec338829c8f9.

Conflicts:
	src/matchers/EXPMatchers+contain.m
Adding subset matcher
Removing examples

my templates went haywire
Fix failure message
Rename containSubset to beSupersetOf
Add string support to beSupersetOf
Revert "Add string support to beSupersetOf"

This reverts commit 3a37168318488d663651dad4dfbbacc896d565d6.
Document beSupersetOf
Merge pull request #55 from robb/subset-matcher

Subset matcher