Draft: Fix size hints when scale > 1

While this fixes #49 (closed), it creates two problems:

• Height is only locked if started in collapsed mode, after going to expanded and back to collapsed, for some unknown reason the size hints are not properly set anymore. I suspect gtk is overriding them.
• Going from collapsed to expanded now preserves the height, which is not desired, the normal behavior is for expanded mode to expand to the last used height.