Use cached 'slice' function everywhere.
Minimize number of created objects in 'extractFunctions' and 'compose' function - decreases memory usage. The stampit.min.js shrinked by 130 bytes down to 6756 bytes.
Implement stampit().combine().
Make sure both 'compose' functions return new stamps always.
Update Readme.md
Chaining code samples fix.
Merge pull request #32 from ericelliott/stamp_compose

stamp.compose() implementation