improve sign summary spacing

[kvesik]

The visual sign summary panel in the main SLPAA window currently wastes a bit of space here and there. This should be addressed, because if the summary takes up a lot of vertical space the user may not be able to see associated Relation and Movement/Location modules get highlighted when they mouse over modules in the visual summary.

Ideas for reducing wasted space:

• remove the blank line that currently shows up next to "Hand 1" and "Hand 2"
• organize points and intervals more efficiently; I initially just put intervals on one (or more if necessary) lines, and points on a separate one (or more), but often we should be able to get both points and intervals on the same line
• possibly reduce vertical height of rectangles/ellipses? or maybe make this a user setting? or maybe it depends on font size, which is a user setting? food for thought.
• ... any more?