While converting IANA registrations for language tags to RDF (for a speedy langtag DB) we ran into the problem of lacking datetime support. We're now working on that.

* [DATETIME_STD,NEW] New module describing the implemented standards for datetime.
* [DCG_CARDINAL,NEW] Added unsigned_number//3 which returns the integer and the fractional components as well.
* [DCG_GENERIC,EXT] Removed support for DCG disjunctions. Users of this module should not use direct disjunction (in the meta-arguments).
* [DCG_GENERIC,FIX] Fixed issues with non-integer values for dcg_multi's between/2 argument by adding a custom predicate dcg_multi_between/3 that takes care of variables.
* [ISO8601,NEW] New module implementing predicates for ISO8601 datetime:
** Calendar day names.
** Calendar months (first day in year, last day in year, number of days).
** Centennial year / leap year / common year.
** Day in week.
** Number of weeks in year.
** Number of days in year.
** Week in year (week in which year?, week number).
* [ISO8601_DCG,NEW] New module implementing a DCG for the datatime formats of ISO 8601 (excluding the extended representations):
** Calendar date representation.
** Local time representation (partially).
** Ordinal date representation.
** Week date representation.
* [IEC60050-111,NEW] New module documenting some concepts drawn from IEC 60050-111.
* [MATH_EXT,EXT] Replaced integers_to_float/3 (+,+,-) with its (?,?,?)-variant float_components/3, also adding its subfunctions float_fractional_component/2 and float_integer_component/2 (which are similar to the swipl builtin float_integer_part and float_fractional_part functions).
* [RECORD_JAR,FIX] Minor fixes.
* [RFC5646_RDF,EXT] Rewrote this module: transform all IANA registry properties to RDF triples. We ran into the problem that the standards support for dates was lacking, so will first add that to RDF datatype assertions and then complete this IANA2RDF conversion.
* [RFC2396_DCG,FIX] Two fixes: is a component is left out it must be verified to correspond to a variable feature in the grammar!
* [ISO8601_DCG,SC] Simplified codebase by creating generic DCG rules for integers and floats. The date and time components are very simple wrappers around there generic DCG rules.
* [ISO8601_DCG,EXT] Fully implemented decimal fractions in the local time format (for hour, minute, and second).
* [ISO8601_DCG,SC] Reorganized the code in this module into sections.