Center fader in its (left hand side) mixer strip column.

Center fader in its (left hand side) mixer strip column.

Attempt to center meter in its as well, but this doesn't seem to be working.
Perhaps this whole section should be layed out as a table to ensure the split
down the middle is aligned no matter what?

git-svn-id: svn://localhost/ardour2/branches/3.0@9555 d708f5d6-7413-0410-9779-e7cbd77b26cf