javadoc - add some javadoc to Messages
messages - improve performance of labels.js[on] generation

especially in DEV mode, where the creation of a resource bundle for each key was especially
bad for performance
core - add getHeader on RestxResponse

This allow to test if a header has been set, useful especially in filters
core - allow to set cache-control header specifically

without needing to disable cache filter for the path
build - allow to use multiple maven fragments contributing multiple plugins config
build - add support for com.sun.tools dependency
add json to list of detected mime types
apidoclet - add some javadoc on a endpoint in samplest
apidoclet - explore doclet possibilities
apidoclet - setup apidoclet on samplest to explore the possibilities
apidoclet - initialize unit test
apidoclet - add some options
apidoclet - implement api notes generation
apidoclet - fix doclet pom

and we'll need to make it generable by restx build
apidoclet - integrate notes in API DOCS web console
apidoclet - minor - fix comment in test
apidoclet - add a runner to ease launching doclet programmatically
apidoclet - review dependencies to prepare auto doclet generation
apidoclet - generate doc in auto/hot compile
apidoclet - use quiet mode to avoid cluttering logs with details on doclet generation