8136930: Simplify use of module-system options by custom launchers
Reviewed-by: alanb, ksrini, henryjen, sundar

8155086: Replace usage of -Djdk.launcher.limitmods in tests with -limitmods
Reviewed-by: alanb

8044773: Refactor jdk.net API so that it can be moved out of the base module
Reviewed-by: alanb, erikj, mchung

8143554: UnsupportedOperationException is not thrown for unsupported options
Reviewed-by: alanb
Contributed-by: Svetlana Nikandrova <svetlana.nikandrova@oracle.com>