Fixup some things in BitArray.

- Convert tabs to spaces.
- Rename TangoUnitTest to just UnitTest to match what the other modules are using (otherwise it breaks the unittester).
Fixes for DMD 2.062 involving T being an array type

Regression coming from Issue 9563
ConstOf HolderOf MutableOf added to Traits.d
Merge remote-tracking branch 'upstream/d2port' into d2port
real is 0 bug !\?fixed