Add newrelic_yml LWRP for easy newrelic.yml manipulation

Usefull to configure multiple Java app on the same host for exemple.
Remove too strict type checks
Replace the template by the newrelic_yml LWRP
Documents + exemple for newrelic_yml
Merge conflict fix(es)
Merge branch 'lapresse-lwrp-for-yaml-file'
Implementation of newrelic_yml LWRP
Merge branch 'feature/newrelic_yml'