Delete node/npm before extracting new npm

If node/npm already exists then we cannot rename node/package to it. Also we don't get a clean install.
Check for modifications before running gulp, grunt and npm install
m2e configuration to run goals during correct build phase

install-node-and-npm on project configuration, when it's first loaded or updated with Maven.

npm, gulp and grunt on incremental so they run when you make changes
Gulp & Grunt mojos check whether the build is incremental
NPM mojos check whether the build is incremental
GulpMojo: also run if package.json is changed

This suggests a more general list of src files in the configuration.
Merge remote-tracking branch 'karlvr/feature/fix-npm-extraction' into develop
Merge branch 'feature/m2e' into develop