Refs #6849. First cut at W transform matrix saving.
Refs #6849. Adding affine matrix saving.

This necessitated making a template version of the matrix saving code, so the
W transform daving routine changed to match.
Refs #6849. Actually use new function.
Refs #6849. Trapping when no affine matrices present.
Refs #6849. Adding id getter for coordinate transforms.
Refs #6849. Changing affine matrix saving.
Refs #6849. Add type of affine transform as attribute.
Refs #6849. Change name for W matrix entry.
Refs #6849. Changing W matrix function and affine transform names.
Refs #6849. Adding loading of W matrix and affine transforms.
Refs #6849. Fixing type issue.
Refs #6849. Handling affine matricies better.
Refs #6849. Fixing warning.
Refs #6849. Fix for failing unit tests.
Refs #6849. Removing debugging.
Refs #6849. Fixing conflicts and changes to function calls.

Merge branch 'keep_6849_MD_metadata' into feature/6849_MD_metadata

Conflicts:
	Code/Mantid/Framework/MDAlgorithms/src/LoadMD.cpp
	Code/Mantid/Framework/MDAlgorithms/src/SaveMD.cpp
Refs #6849. Adding doxygen for SaveMD.
Refs #6849. Removing unneeded W matrix loading.
Refs #6849. Adding doxygen for LoadMD.
Refs #6849. Adding SaveMD unit test.