Review Request: JDK-8164689: Retrofit jar, jlink, jmod as a ToolProvider

[Mandy Chung]

This patch updates jar, jlink, jmod tool to be a provider of the new tool SPI.  Some tests are also updated to replace the use of internal APIs with ToolProvider::findFirst to look up a tool provider.  There are more tests that can be updated and something to be cleaned up in the future.

http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8164689/webrev.00/index.html

thanks
Mandy