Moved all commands into new cmds/ directory
Added basic bash completion script
gencode: removed the generators

I'm getting rid of the generator for now. I need to reimpplement the import
mechanism, and I want to get tab completion working first.
gencode: added GenerateCPP and GeneratePython stubs
cmds/parser: added OptionParser
cmds/genpy: rewrote generator and command
gencode: delegates to commands

The import part of this change is that gencode now uses the OptionParser, and
delegates to commands. However, one small but important change is also that the
script specifically runs with python2 because of issues I had with the import
mechanism in python3 (something that I want to address later).
cmds/genpy: moved file writing into PythonGenerator
cmds/gencpp: rewrote the CppGenerator
cmds/gencute: deleted gencute.py
cmds/genqml: deleted genqmlp.py
cmds/gentornado: rewrote tornado generator
cmds/genbase: deleted genbase
cmds/gemake: rewrote genmake
cmds/gencpp: implemented header include
cmds/gencpp: added support for multiple targets
cmds/genpy: automatically added .py to target
cmds/genpy: added support for multiple targets
gencode: deleted dead code
cmds/gentornado: automatically append .py to target