Introduce [Version (...)]

Introduce [Version (...)]

Parameters:
 since: string, version number
 experimental: bool (was: [Experimental])
 experimental_until: string, version number
 deprecated_since: string, version number (was: [Deprecated (since="")])
 replacement: string, symbol name (was: [Deprecated (replacement="")])
 deprecated: bool (was: [Deprecated])

Used symbols labeled with [Version (since = "")] are checked
against the locally installed package version.

Use --disable-since-check to avoid this behaviour.

Fixes bug 678912.