Created a method to create a Team as well as the related TeamNode in the same
call.  Refactored all the code that creates both to call the new method ...
except in 3 cases where the receiver is computed at run time, or the
team name is changed after the Team is created.

Removed redundant methods that did this work in 4 classes.
Corrected capitalization of "Ok" in due_dates.rb, in order to allow
metareviews by default during a metareview period.
Fix usage of old(?) method name, which prevented reviews from being saved.