Cleanup Jetty 10 Start

[joakime]

Jetty version
10.0.0

Description
Some changes discussed.

1. Change --list-modules shows a single line for each module. (the name and the first line of description)
2. Add --show-modules for the full / detailed module list
3. Deprecate --create-startd (show warning)
4. The behavior of --create-startd is set to default mode, creating files in ${jetty.base}/start.d/ by default.
5. Create new --create-start-ini to force older operation in start.ini
6. Add new --add-modules=<name>,<name> option (plural form)
7. The start.d vs start.ini default mode is dependent on the existence of start.ini (if it exists, the --add-modules=<name> default to adding to start.ini, otherwise it uses the new default of start.d)

[sbordet]

@gregw we have add-modules already in the [jpms] directive in a *.mod file.
How about --enable-modules instead?

[gregw]

I think we need the word --add in there some where to distinguish between --module=foo which enables module foo for this run vs --add=foo which persistently adds the module to the base for all future runs.

If there is already a --add-modules, then I think we go with just -add as an abbreviation of either --add-to-start or --add-to-startd, whichever is in-use or the default.

[sbordet]

@gregw however, both in the documentation and in the output of the command:

INFO  : server          transitively enabled, ini template available with --add-to-start=server
INFO  : logging-jetty   transitively enabled
INFO  : http            initialized in ${jetty.base}/start.d/http.ini
INFO  : resources       transitively enabled
INFO  : threadpool      transitively enabled, ini template available with --add-to-start=threadpool
INFO  : logging/slf4j   dynamic dependency of logging-jetty
INFO  : bytebufferpool  transitively enabled, ini template available with --add-to-start=bytebufferpool
MKDIR : ${jetty.base}/resources
COPY  : ${jetty.home}/modules/logging/jetty/resources/jetty-logging.properties to ${jetty.base}/resources/jetty-logging.properties
INFO  : Base directory was modified

The word "enabled" is mentioned multiple times - it's exactly what we do, we enable the module permanently.

[gregw]

1. and 2. are done in Issue #5254 List/Show modules #5257