Provide packages.join_name() for creating a valid package name from a family name and a version.
Add rez.package_maker: provides utilities for writing package files.
cli.main: simplify and clarify parser setup process
rez.cli: return to the original modular, plug-and-play design for command-line tools.  each sub-module is completely self-contained, with a function for setting up the parser and one for the command itself.  the speed is equivalent to the design it is replacing and all features of argparse are fully supported.
rez.system: convert property decorators to rez.util.propertycache to cleanup the code a bit.
Remove .pydevproject.
Not sure how it got in there since it was added to .gitignore.  maybe a glitch with smartgit.
rez.resources:  rename MetadataValidator to MetadataSchema.  "Schema" is a more accurate and familiar concept.
Move expansion from !OLD! to {new} into convert_old_commands()
Merge branch 'nerdvegas/versions'

Conflicts:
	src/rez/cli/forward.py
	src/rez/cli/main.py
	src/rez/cli/settings.py
	src/rez/cli/test.py
	src/rez/resolved_context.py
	src/rez/resources.py
-merged with chad's 2.0 branch, all unit tests passing now
-rez-exec renamed to rez-interpret