New vim plugin by Christopher Zimmerman
add --indent-empty switch

to force indenting of empty lines. Needed for new vim plugin
further improve new caching vim plugin

* consistent naming of line numbers.
* call remove() only once.
* don't overwrite, but only add to formatoptions. Don't add 't'.
* use new --indent-empty command line option.
Merge pull request #153 from madroach/vim-caching

new vim plugin with caching using the native indentexpr