Docker-hica

Added a new library injector that can be used to pass through a set of libraries from host to container

- Added injectors folder to MANIFEST.in
- Tweaked the injectors search glob to match only `*.py` files

- First release published as `pip` package
- Two new injectors
- Tty injector for when the process needs input
- Command aliases allowing one to specify complex command aliases via labels, see the signify image for example
- All example images ported to Fedora 23 base
- Except for `test-descriptions` which is based on `busybox`
- More conservative subprocess usage in `introspect_runtime` injector
- DRI injector bugfix for NVIDIA devices
- Documentation update

First public release