A batch of changes, mainly to the text copy, to improve readability.

Tree windows have informative titles; reconciled tree window includes
color key; "about" accordion completely rewritten to describe (to a
similar level of detail) steps, data sources, architecture, credits;
added "going further" pane to accordion.
 merging due to some glitches with graphical git client.
Merge branch 'master' of https://github.com/phylotastic/phyloShiny