Allow setup to parse more than 3 versions from the setup.ini file

Allow setup to parse more than 3 versions from the setup.ini file

This recognizes any "[foo]" line as introducing the information for another
version, which doesn't have one of the trust levels [curr], [prev] or
[test], and so isn't automatically selected when setup is told to install
all packages at that trust level (by default, [curr]).

Setup already does all the necessary sorting in version order etc. to use
these additional versions.

The value of <foo> carries no meaning, but the setup.ini specification
will be amended to mandate the use of "[ver<digits>]".

	* PackageTrust.h (trusts): Add TRUST_OTHER.
	* inilex.ll: tokenize any other [version] as the T_OTHER token.
	* iniparse.yy: Add T_OTHER token and set package trust
	to TRUST_OTHER when it is used.

Signed-off-by: Jon Turney <jon.turney@dronecode.org.uk>