Possible fix: Using extend() with Moment's prototypes breaks IE < 9

https://github.com/moment/moment/issues/1114
Changed to the simpler workaround rather than full blown fix.

https://github.com/moment/moment/issues/1114#issuecomment-24629678
Adjust indentation
Improve Duration function by normalizing the input object.
Created a new function (normalizeObjectUnits), this is now also used by dateFromObject

Fixed spacing or jshint

Fixed missing argument
Merge pull request #1116 from Xotic750/DurationNormalization

Improve Duration function by normalizing the input object.
Merge pull request #1115 from Xotic750/extendDontEnum

extend() now works on IE < 9