web/username_prefix.php: comment prefixes: support embedded ":" in comment

schemas/VegBIEN/VegBIEN data dictionary.xlsx: updated: populated some definitions from VegCore data dictionary where available

bugfix: schemas/VegBIEN/VegBIEN data dictionary.xlsx: updated: restored "" that had been stripped out when the data was copied out and pasted back, due to a bug in Google spreadsheets. prepended : before initial " as a workaround to prevent the " getting stripped out again.

schemas/VegBIEN/VegBIEN data dictionary.xlsx: updated

schemas/public_.sql: analytical_stem_view: applied data dictionary renamings, using the steps at wiki.vegpath.org/VegBIEN_schema_refactoring#apply-data-dictionary-renamings-to-database

web/username_prefix.php: user2path(): comment prefixes: documented how to put the comment on a separate line when word-wrapping (c-_:x@url). this format works in Google spreadsheets.

web/username_prefix.php: user2path(): comment prefixes: documented how to put the comment on a separate line when word-wrapping (c-_:x@url). this format works in Google spreadsheets.

web/username_prefix.php: user2path(): added support for comment prefixes, which can be used to include term categories. note: when URL is used without http:// , you must include a non-letter in the comment (eg. c_:x@url) to work in Firefox.

web/username_prefix.php: user2path(): visually separated steps for easier readability

fix: schemas/VegBIEN/VegBIEN data dictionary.xlsx: updated: restored "" that had been stripped out when the data was pasted in. set column widths to fit on a laptop screen.