default to latest versions of node and npm
choose default version using semver
update to node 0.10
Merge pull request #31 from heroku/update_default_versions

default to latest versions of node and npm
cat npm-debug.log on exit
Merge pull request #34 from ryanbrainard/cat-npm-debug-log

Cat npm-debug.log on exit
add CONTRIBUTING.md
remove extra newline
update 'no version specified' devcenter url
Merge branch 'master' of git://github.com/heroku/heroku-buildpack-nodejs into cache_clearing

Conflicts:
	bin/compile
updating node versions and defaults