Do not strip metadata.  This was done for the sake of memcache, but it complicates the code because rez needs to maintain and separtely cache two versions of the metadata, stripped and unstripped.
Fix a bug related to earlier refactoring of PackageVariants to contain PackageRequests instead of string requests.
Fix a bug related to refactoring of metadata to be tradiational dictionaries instead of AttrDict instances
Code cleanup and documentation improvement
Certain env variables have special meaning to python and rez and should affect the current running python session when using a Python command interpreter.
Rename rez_release to release.
Rename rez_filesys to filesys.
Rename rez_parse_request to parse_request.
Rename rez_memcached to memcached.
Rename rez_util to util.
Rename rez_config to config.
Rename rez_exceptions to exceptions.
Merge branch '2.0'

Conflicts:
	python/rez/resources.py
remove stray print statement
Merge branch '2.0'
package rename bugfix
Merge branch '2.0'