TODO.txt

Validate term name - combination

	If target collection is CombinationCollection then validate name against combination:

	E.G. CORDEX RCM Model: [wcrp:global:institute]-[rcm-name]
	This is more complex as the validator will need to split the term name and validate each split member.

Ensure term rewriting only occurs when term has changed

	Need to ensure that writes only occur when the term information has been touched in some way otherwise there will be false commits

Custom Collection for non-enumeration Terms

	Some DRS facets are not an enumeration of allowed values but refers to a “pattern” or a combination of other facets:
	Examples:
	CMIP6 Ensemble -> r[0-9]i[0-9]p[0-9]f[0-9]
	CORDEX RCM Model -> [institute]-[rcm_name]

	Add a custom RegExCollection instance that would not have term files but rather a regular expression to constrain term names within the collection.
	Add a custom CombineCollection instance that would not have term files but rather a collections uid pattern to build term names from other collections.
	Those custom collection should be able to propagate the validation/check methods depending on the RegEx or the terms from the other collections.

Add DRS info at Scope level 

	Add DRS info at the Scope level about dataset ID, directory and filename format, through the MANIFEST:

	Example:

	cmip6 = pyesdoc.cv.load_scope('wcrp', 'cmip6')
	print cmip6.data.dataset_id_template
	print cmip6.data.directory_format
	print cmip6.data.filename_format