New design: Humanizer members moved to instance

Adapted tests.
There is an issue with the rounding of the last unit: currently the code
only checks if the last unit in the count has been reached, and not if
it is the last unit we want (UnitToDisplay), so one of the test breaks.
That's why we need way more unit tests :-)
Added unit tests to demonstrate rounding issue

The fractional display doesn't work when limiting the units to display
Added a Parameter class with a Builder

To ease the Humanized creation that was going to degenerate quickly.
Lots of fixes for various issues

Most of the issues were included with the "units to display" parameter.
There is still a lot to do.
Improved rounding code but some unit test fail

Need to work a bit more on the rounding of all units (instead of the one
just after the last unit to display)
Still some more work to do but getting there :-)
All working, now need to write some documentation
Merge remote-tracking branch 'upstream/master'
Minor changes before pull request
Merge pull request #12 from Pvlerick/master

Major changes implemented