Minor performance improvement and fix

Improvement:  Rework Number constructors to parse[Int|Float]    (minor
performance improvement in code used for older implementations);
(http://stackoverflow.com/questions/4090518/string-to-int-use-parseint-or-number);
(for consistency with other string-to-number conversions).Bug fix:
Suppress variable 'time' which was contributing for global scope
pollution    (also, another slight performance improvement result of
the suppression itself and the implicit minor code rework).