Support Java 9

[yaohaizh]

1. Java 9 is officially out
2. The JDT.LS is WIP here: https://github.com/eclipse/eclipse.jdt.ls/pull/324/files

We need prepare the support for Java 9

[testforstephen]

TODO:

• Support set breakpoint in java 9 source file.
• Auto detect the project is modular project or not.
• Auto resolve module path from project settings.
• Auto resolve main class from module.
• Support launch options in java 9. (e.g. --module-path, -m)

[testforstephen]

Implemented by PRs:
#124
microsoft/java-debug#90