* Increase minimum height of headerWidget in ExpansionPanel to smooth the animation.
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Add regression tests that check for equal height of header elements in ExpansionPanel.
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Clarify comment.
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Reduce padding in ExpandIcon to 12px s.t. header height is 48px.
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Update testcases to new header height (56px -> 48px).
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Test for header height equal to 48px.
Signed-off-by: Morris Kurz <morriskurz@gmail.com>

* Change issue number to link in comment

* Add periods to comments
Signed-off-by: Morris Kurz <morriskurz@gmail.com>