8180745: Add --release 10 as an alias for --release 9
Reviewed-by: mcimadamore

Merge

8178152: Handling of incubating modules, the jdk.unsupported module and --add-exports with --release <current>
Summary: --release 9 should only allow documented modules; --add-exports/--add-reads/--patch-module should not be allowed on system modules when --release 9 is used.
Reviewed-by: jjg, erikj, ihse

8028544: Add SourceVersion.RELEASE_10
8028546: Add -source 10 and -target 10 to javac
Reviewed-by: jjg, smarks

8153391: an image created for \"jdk.compiler\" fails to run javac
Summary: Improving errors produced by javac when the zipfs implementation is missing in the JDK image.
Reviewed-by: jjg

8145342: Some copyright notices are inconsistently and ill formatted
Summary: Adjusted formatting of copyright notices.
Reviewed-by: darcy, alundblad

8072480: javac should support compilation for a specific platform version
Summary: Adding a new javac option for compiling for JDK N: -release N; including history data for previous version of JDK.
Reviewed-by: erikj, ihse, jjg, mcimadamore, mr
Contributed-by: jan.lahoda@oracle.com, erik.joelsson@oracle.com, jonathan.gibbons@oracle.com