1 new fix; I'm confused

The change to  Library/Michigan/precalc/4e/Chap1Sec2/Q23.pg  is new (9-Feb-2014).

I am a bit confused about the rest.
0)  This work is being done on a new MacMini which has an exact copy of the working copy I checked out on my old iMac.  Before making today's edit, I used the command
        git pull upstream master
and was walked thru a 2-stage process to assent to Xcode license agreements and accept the RSA key fingerprint for github.com (192.30.252.130).  [Both my public and private keys were copied from old to new Mac.]

1)  After the 1-character change in  Michigan/precalc/4e/Chap1Sec2/Q23.pg and git commit -a (in top of the tree), the git push command took about  5 minutes to complete with the following messages when done:
    Counting objects: 42071, done.
    Delta compression using up to 8 threads.
    Compressing objects: 100% (8272/8272), done.
    Writing objects: 100% (25962/25962), 5.62 MiB | 56.00 KiB/s, done.
    Total 25962 (delta 21772), reused 21690 (delta 17613)
    To git@github.com:Dick-Lane/webwork-open-problem-library.git
       e99e633..defe87d  master -> master

2)  After logging-in to github and submitting a Pull Request, I see 5 commits.  The Nov 25 item looks like something for which I should have submitted a Pull then.  If the Dec 10, Dec 21, and Feb 9 merge are benign, then I would welcome suggestions about relevant documentation I should read to understand why they appear now.

thanks,
dick