Review Request: JDK-8174739: Rename JMOD section name for native libraries from native to lib

[Mandy Chung]

http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8174739/webrev.00/

This renames the JMOD section name from `native` to `lib` that would
map closely to the directory in the run-time image (with the exception
on windows DLLs that go to image/bin directory).

jlink defines a scheme to name a non-java resource entry in each module for plugins to lookup/add/remove from the modules:
  /$MODULE/$JMOD_SECTION/<path>

jlink will write such entry to image/<dir>/<path> according to the jmod section:
  conf    -> image/conf
  bin     -> image/bin
  man     -> image/man
  include -> image/include
  native  -> image/lib with the exception on windows DLLs goes to image/bin

For example --exclude-files plugin uses this naming scheme to specify the files/patterns in non-classes JMOD section and this change would make it more intuitive what to specify.

Mandy