Fixing o.m.cmap.NaturalEarth build

- Fixing build
- Adding org.mwc.cmap.combined.feature/root_installs/DebriefTutorial.pdf to .gitignore
This file will be created when building
- Removing org.mwc.cmap.NaturalEarth/test_data - will be added to the test plugin
Adding o.m.c.NaturalEarth.test plugin
Adding ShapeFileTests
Merge pull request #992 from pecko/issue984_snpe

Issue #984 - Adding o.m.c.NaturalEarth.test plugin