Add a Monoid/Semigroup instance for Maybe.
Added CONTRIBUTORS file. Feel free to edit :).
Update CHANGELOG
Merge pull request #151 from LeifW/monoid_instance_for_maybe

Add a Monoid/Semigroup instance for Maybe.
Merge branch 'master' of github.com:edwinb/Idris-dev
Fix compile error
javascript strHead & strTail primitives
javascript: fixed streq bug
javascript: added StrCons primitive