Merge pull request #22 from greenbits/master

Use npm binary by symlinking correct npm-cli into vendored node
Inject ENV variables and allow for cache rebuild via ENV setting

Killing two birds with one stone:
closes https://github.com/linemanjs/heroku-buildpack-lineman/issues/24
closes https://github.com/linemanjs/heroku-buildpack-lineman/issues/25

We inject variables as suggested in:

https://devcenter.heroku.com/articles/buildpack-api

and then look for the presence of a CLEAR_HEROKU_BUILD_CACHE variable
as a flag to remove all of the cached NPM packages prior to doing "npm
install".
Merge pull request #26 from mdoel/master

Inject ENV variables and allow for cache rebuild via ENV setting
Don't install bundler/sass documentation
Merge pull request #29 from kytrinyx/skip-docs

Don't install bundler/sass documentation
cleared up some of the custom apache modules info
Merge pull request #31 from jasonkarns/patch-1

cleared up some of the custom apache modules info