vtag: keys must have # (or examples in help are wrong)

[brianmajor]

vtag --help says vtag vos:RootNode/MyImage.fits quality=good should work, but it does not--it results in an invalid URI error.

If you use a full vos URI like ivo://cadc.nrc.ca/vospace/user#quality it works.

If you use just the value prefixed with # it works. (#quality)

Looks like the conversion from the fragment to full URI isn't inserting the hash mark.