Adds a function/command to format the current xml file using xmllint --format. The command is mapped to ":FX" run this in any xml file. If there is an error the error will be shown. This requires xmllint to be installed and in your $PATH.
From the command line run the following:
mkdir -p ~/.vim/plugin
cd ~/.vim/plugin
wget http://raw.github.com/johnbradley/vim-fix-xml/master/fix-xml.vim --no-check-certificate
then add th following to ~/.vimrc:
:command FX :call FixXML()