LIFReader: Add User-Comment tags to the series metadata
XMLTools: sanitizeXML does not strip newlines
NativeND2Reader: Don't call sanitizeXML on non-XML data

Add separate sanitizeControl function to handle text.  It's
internal to this reader at the moment, because its replacement
rather than removal of characters does not match the behaviour
of the other helper functions in DataTools, and this reader is
currently the only user.
Merge pull request #363 from rleigh-dundee/lif-usercomment-dev44

Backport of PR #305 to 4.4