date.js intern conversion

mostly 1-1 conversion from doh's date.js. i've only tidied up in intern suites and put in newer dates.

i wasn't sure about keeping getTimezoneName content as it is (ie. testing on different browser/os)... i left so in the end as detecting the tester's chosen browser/os and then calculating TZ is basically doing the same thing the actual method does... however, if we are to keep the browser/os asserts as they are, we better put   data from newer browser/os versions...