Add click generic options

Add generic functions to create click options:

• boolean based option
• list of float based option
• open file mode option

bob/extension/scripts/__init__.py

 from .new_version import main as new_version
 from .dependency_graph import main as dependency_graph
 from .main_cli import main as main_cli
+from . import click_helper
 
 # gets sphinx autodoc done right - don't remove it
 __all__ = [_ for _ in dir() if not _.startswith('_')]