[FEATURE][composer] Finer control of frame and annotation display

Previously, for rotated maps or reprojected grids, the composer would
draw all coordinates for every map side. This resulted in a mix of
latitude/y and longitude/x coordinates showing on a side. This change
allows users to control whether they want all coordinates, latitude
only or longitude only for each map frame side. Similar options have
also been added for controlling how a map grid frame is divided.

In related news... the composer map dialog is now the ugliest,
most cluttered and un-user friendly dialog in all of QGIS. I'd
love suggestions/mockups from the UX team for ways this could
be improved.