Solved 113 to test auto updating of check boxes.
Get rid of git pull --rebase
Rip out student_code for DS.
Added rebase-all.sh
Added exercises 122, 123, 125, 126, 127, 128, 129, 130, 131, 132.
Added git checkout master to rebase-all.sh so the list of branches is correct.
Merge branch 'SL'

Conflicts:
	rebase-all.sh
Solved 113 to test auto updating of check boxes.
Rip out student_code for DS.
Need git checkout master at end of rebase-all.sh too.
Merge remote-tracking branch 'origin/SL'