Switch away from *scratch* when starting a server

Otherwise, things like ido-mode will consider *scratch* visible and may try
to switch to the invisible server frame when asked to view *scratch*.
Debut of git-commit-mode.
Remove latex settings only valid for org < 8.0
Don't re-export org latex files upon saving

Never really used it, and sometimes put a new Emacs process in an
infinite loop on every save.
Should use ez-shell if you need a binding for exporting files to latex.
Remove functions for invoking latexmk within Emacs

Should do this with ez-shell or an actual shell.
Document purposes of Tex variables
Remove obsolete shell-mode customizations

They were commented out already.
Merge branch 'cleanup'
Add basic shell-mode customizations