Update 04_git.tex

Added information about how to store repositories on stats servers using ssh. Did not include information on making these available on https nor the pretty html based frontends (like gerrit)
Update 04_git.tex

Updated Spelling Mistakes.
Lec 4 (git): move UW Stat slides to the end

 - other cosmetic changes; split it across 3 slides
 - add some notes
Lec 7 (clear code): notes on the only 2 slides I have so far
Lec 7 (clear code): Add slide with a comic
Lec 6 (Organization): cosmetic changes
Lec 6: Add points from the discussion to the slides' notes
Lec 6: Remove "only notes" from the Makefile
Move the common header stuff for lecture slides into LaTeX/header.tex
Make slides in the notes versions have a light background
Add another fig for Lec 6 (clear code)
Finish off lec 7 (writing clear code)
Lec 7: remove trailing white space
Add links to code examples, for lec 7
Minor change to 07_ClearCode/Examples/ReadMe
Lec 7: a number of small changes
Lec 7: Add another slide about functions
use 'include' in lecture Makefiles.

- move common things into ../MakeSrc.mk
- put "include ../MakeSrc.mk" in each Makefile that need these
- easier to update and track the updates.
Remove Lectures/.gitignore; no longer used
Rename MakeSrc.mk -> MakeSrc_lectures.mk