install feature-mode.el package to edit gherkin

files for the ruby cucumber gem
Merge feature-mode to personal branch
rm git-svn support

I don't want git-svn support as I don't have svn installed on most
machines many magit commands such as commit and push fail with

    require: Cannot open load file: magit-svn

so I am commenting out purcell's code. A conditional would be more
useful upstream.