Merge pull request #3 from tgrk/master

Allow map and foldl to handle hours
Badarg on incorrect input.
Add type spec, restructuralize module
Merge branch 'master' of git://github.com/knutin/edatetime

Conflicts:
	src/edatetime.erl
Merge branch 'master' of github.com:tgrk/edatetime

Conflicts:
	src/edatetime.erl