#1261: Handle duplicated files.

Update the one in use with better data from the one not in use, then delete the one not in use.
#1261: Everything appears to work. Now to test on prod data.
Remove sorting, filtering by author, and turn back on publication list caching, #1366
Began OS Migrate docs.  #767

known_issues.md is mostly complete.  It lists the things that didn't migrate so well that needed manual fixing later.  I went through all the old tickets to find issues for this.

readme.md is about half done.  It details configuring and running migrate, but glosses over the rest of the setup.  Not sure how much detail is needed here.  This document will benefit from review by someone who hasn't already been through the migration process a couple hundred times.

development.md needs the most work.  I provided links to some of the posts I used for reference because I'd like to keep the scope of this to extending OS's implementation of migrate.  No need to reinvent the wheel with intro to migrate content.
Small wording changes for site creation link/button.  #1351
#1261 #1370: Add one-liner documentation. Try to catch PDOException and gather more information about it.
Nortony theme: fix header 2nd issue (was pushing into header 3rd if site info had long text)
Aglet theme: black and grey flavor - add slightly more bottom padding under logo.#1356
#1261: Comments.
#1261: Wrap another possible exception in try..catch
#1261: Try new way of skipping unprocessable files.
#1261: Only attempt to skip if we have something to skip.
#1377 We should only pass through the selected publications as biblio filter parameters
Merge branch 'SCHOLAR-3-0' of github.com:openscholar/openscholar into SCHOLAR-3-0
Merge branch 'SCHOLAR-3-0' into SCHOLAR-3.1