Merge pull request #25 from vholland/sdo-music

Add music vocabulary per rvguha#152
Fixed mistake in itemList element description.
"It should say “Use ListItem with a ‘position’ property…” not “Use ItemList…”"
(Reported by Tom Marsh)
Missing ')' in definition of salaryCurrency.
homeTeam, awayTeam now anticipate Person + SportsTeam values.
There was a bug in the RDFS syntax, and also we
did not use SportsTeam, only Organization. Finally the
definitions expected Person but the wording didn't explain why.
Added VideoGame definitions. Copied Music into main file.
Fixed recordedAt/recordedIn inverses to point to each other.
Removed older duplicate recordedAt definition.
Removed separate schema file for Music.
Explicitly scoped to Microdata.
Also tweaked intro sentences, used Wikipedia for spec references.
Github link.
Added 'or action' since actions (at least PlayAction) might have events.
rvguha#147
Fixes rvguha#126 -schema:attendees superseded by schema:attendee
Applying https://github.com/rvguha/schemaorg/pull/128/commits manually.
Thanks Sachini :)
Removed 24x "legacy spelling; see singular form," etc.
rvguha#153
This text no longer needed as we have built-in
supercededBy site navigation.
Backed out bad wording on homeTeam, awayTeam; adding competitor.
The competitor property is a super-property of homeTeam, awayTeam
that can be used for a broader range of sporting situations.
Documented addition of 'competitor'
Adjusted case to match subproperties.
First cut from Tom following discussions last week. I made
some hopefully minor changes, noted in the file.
Simplified startDate,endDate to say item rather than list types.
This is needed as we are adding it to DatedMoneySpecification.
Adding DatedPriceSpecification type and currency property.
Markup fix.
Linked github.
https://github.com/rvguha/schemaorg/issues/163
Noted that 'amount' was also added.
Better summary of sdo-venkman.