Mechanism for vendored and binary files.

- Added Makefile to download the vendored and binary files.
- Replace gen-ssh-config with the said Makefile.
- Update all sorts of Bash completion files.
- Added `kompose` Bash completion file.
- Replace pythonrc submodule with said Makefile.
- Replace `bfg` shell function with said Makefile (and short shell
alias).
- Update Git hook to use Makefile, remove whatever was removed.
- Added `rc_update` shell alias to force update all said files.
- Added `kind` Golang binary.