set maximum size hint to stop port matrix windows being resized beyond their useful size; remove visibility checkbuttons -
visibility now controlled through menu or by clicking on group names; port groups fold down to a small tab when hidden;
don't swap the orientation of the matrix once it has been opened.
git-svn-id: svn://localhost/ardour2/branches/3.0@5373 d708f5d6-7413-0410-9779-e7cbd77b26cf
for ins and outs. The matrix will now be arranged so that more ports are labelled
horizontally than vertically, to aid readability.
git-svn-id: svn://localhost/ardour2/branches/3.0@4467 d708f5d6-7413-0410-9779-e7cbd77b26cf
