Merge pull request #56 from martijngastkemper/master

Fixed link to anvil-cli repo
php-5.6.0RC2
newrelic-4.10.1.62
less confusing status update messages
change from manual check to using composer to see if the buildpack was installed as a production dep
use new stack-aware buckets
use external service for resolving HHVM/PHP engine requirements, now from composer.lock if possible and using version selectors
disable new relic during builds and make it log to stderr, not stdout
nicer message on default runtime selection
better handling of missing composer.lock
fix indent for lines after the first; doesn't work this way after all
nicely fold list of available runtimes on error
Merge remote-tracking branch 'upstream/master' into master
fix (and clarify) error message on composer.lock parse failure; point out it must not be empty
colon to dots for consistency
raise default log level for new relic to prevent clutter in the logs (e.g. from every CLI invocation during boot)
some error message and handling fine tuning
force newrelic to log to stderr; stdout interferes with boots
drop annoying links to dev center, they're more confusing than helpful
grammar