-some python2.5 compatibility
-moved platform_py to system.py, turned into singleton
-added shell detection to system.py
-improved on existing shell detection via psutil module, this is also x-platform
-added settings API
-removed some settings from configure/install.sh, now handled at runtime by settings singleton instead
-fixed rez-dot so you can change img format; changed default from jpg to png,
 jpg has issues on old centOS distros;
-added rezconfig file, part of new settings system
-ported Rex to use system.py
-removed some now unused settings from configure.sh
-removed version.sh, inlined into install.sh
-generalised source retrieval code from builds.py, now resides in build_utils.py,
source_retrieval.py and new plugins. This functionality was tied into pkg
src downloading, but the new rez-install tool needs it in order to d/l and
update formulae repos.
-new entry point for downloading src is source_retrieval.get_source()
-NOTE existing builds.py is unchanged, but will need to be deprecated as there
is duplicate code, I have not had time to do this. pkg-specific code should
probably be put into a new 'build_package.py' file.
-added yapsy-based plugins for source retrieval - 'archive', 'git'. Hg not
done yet.
-added general plugin manager
-added zip support to archive downloader.
-added some py2.5 compatibility.
-fixed minor bug in git cloner when using revision HEAD
-ported Hg cloner to yapsy plugin
-added yapsy to installer
-removed new build_utils.py file, the url safe encode/decode to filesystem funcs are now in util.py
-fixed some bugs in new plugin-ized cloner code
-ported remaining code from builds.py into build_package.py. builds.py is
left for clarity but it will need to be deprecated.
-added rez-install subcommand. Doesn't actually install pkgs yet, but does
 all the formulae repo management.
-misc python2.5 compatibility, unfortunately we need it here at Method
-see previous commit
-ported remaining use of settings to new settings code
-removed all references to filesys.py
-removed filesys.py
-added rez-settings tool, which views current settings
-updated resolver code so that packages_path can be passed to the resolver,
this cleans up code in rez-env autowrapper
-fixed bug that meant subshells were broken
-misc python2.5 compatibility

Merge branch 'luma_ext_blds' into rez_install_cli
Conflicts:
	bin/_set-rez-env
	configure.sh
	install.sh
	python/rez/config.py
	python/rez/release.py
	python/rez/util.py
-added new warning setting, warn on old commands
-moved _joinrealpath over with other backports
-fixed bug in build process
-ported formulae_manager to use resources
Merge branch 'nerdvegas/rez_install_cli'