support for multi-module maven projects

[JoshLitt]

Meghanada doesn't seem to work as well as it could with my multi-module maven project. Maybe I just don't understand how to configure it correctly (if so, they a section of the README.md for that would help).

According to (meghanada-show-project), it thinks the project root is the sub-project containing the source I'm looking at. This means it has trouble finding sources in the other sub-projects of the project. Also seems to have trouble compiling files in the sub-project.

[pkvov]

idea will create a parent maven project
i just create a empty class in the parent folder(with a src/main/java/test.java), then restart meghanada-server, finally it will find the right maven project