fix for expanding month, as well as more consistent behavior on displayMonth

[zachtib]

I noticed that displayMonth was behaving strangely when the selected date (ie today, August 2) was in a different month than the beginning of the week (today that would be last Sunday, July 29). The display at the top would always show the month corresponding to that Sunday, rather than the selected date. To fix this, I've changed displayMonth to generate off the selected date by default, or beginning/ends of week when using the next/previous week buttons.

The childAspectRatio change was something I took from a GitHub issue where the calendar would not expand, which was behavior I was seeing as well. I don't know is this is the ideal fix, but it does fix the issue in my project.

[ericwindmill]

hey @zachtib I couldn't merge this because we made other updates and the conflicts were more headache than just rewriting your updates. BUT you were right on both accounts and THANK YOU and apologies for taking so long to get to this.