Define g:snips_author

Use my local username by default. Still not sure about this, so I'm
leaving the (updated) code in local_templates/local.vim too.
Remove vim abbrev (convert to commands or snippets)

sub: Add shebang snippets and clean up cpp snippets in david-snippets.

abbrev has the ability to mess up my typing. I have snippets which
generally replace them. I've kept my jnew abbrev (someday I can figure
out how to convert to a snippet) and include/define (I actually use
them).

Gets rid of lots of abbrev:
* Change shebang abbrev to snippets.
* Change Cscope abbrev to command.
* Remove unused java package abbrevs.
* Remove abbrev that were long ago replaced with snippets: for loop,
  pragma optimize, and include guard.

Comment out redirect abbrev. I haven't used these in ages and they don't
seem worth their own commands.

Set snippet dir so I can use :UltiSnipsEdit to edit my personal
snippets.
Add a newline in commit buffer

fugitive/git's commit buffer doesn't have whitespace around the comment
boilerplate ("Please enter..."). That makes it harder to use the `ip`
motion since the comment is part of the current paragraph.
Change Q to not move cursor

I noticed myself re-positioning the cursor. Change my map to use the
smarter version.
Use C-l to refresh gitv and fugitive

Add <Plug>(david-redraw-screen) for all plugins to use. It clears search
highlighting and redraws the screen.

Create remappings for C-l in gitv (browser) and fugitive (status)
instead of their arbitrary commands. Must be nmap (not noremap) because
I'm remapping to their commands (they don't provide Plugs).

Update netrw to do the same plug dance and now it also clears search
highlighting and redraws the screen.