Introduce child injectors
Make inject decorator work also on classes and save some keystrokes
Fix typo
Merge branch 'master' into child-injectors

Conflicts:
	injector_test.py
Add missing documentation and tune code a bit
Merge pull request #12 from jstasiak/child-injectors

Introduce child injectors.
Merge pull request #16 from jstasiak/class-injection

Make inject decorator work also on classes and save some keystrokes.
Bump to 0.6.0.
0.6.0 merge.