Add missing dollar to variable expansion
Merge branch 'bug/misseddollar'
Break out Vim's file type detection from .vimrc

Vim's file type detection doesn't need to sit in .vimrc.  Keep things
clean and break out the markdown detection.
Merge branch 'ftdetect'
Don't attempt to install already-installed stuff

If the installed file/folder is already installed, don't attempt to
install it again.
Merge branch 'skip-unneeded'
Use normal indentation in shell scripts
Only highlight tabs where they're unexpected
Use tabs in the install script
Merge branches 'whitespace' and 'rewhitespace'
Use spaces for tabs, not "^I"
Merge branch 'whitespace'
Use four spaces for Markdown indentation
Merge branch 'markdown-indents'
Check spelling in Markdown files
Use bash's `type`-style formatting for whitespace
Use four-space indents in install.sh

Bash's `type` output uses four-space indents, so follow its lead.
Keep compound Bash statements on one line

Bash's `type` output has if/then, while/do, etc statements on one line.
Follow its lead, except where that would lead to over-long lines.
Merge branch 'shell-standards'
Reset OPTIND between getopts invocations

Bash doesn't automatically reset `$OPTIND` between unrelated invocations
of `getopts`.  Which means multiple unrelated calls to `getopts` can
cause badness.  Don't do that.