Make Kodkod work with Alloy

- Some new files were added to the multiobjective package
- Kodkod options was updated for multiobjective options
- Stubbed out the overflow functionality
  - Alloy expects this but the changes were too invasive to include

The corresponding changes to Alloy are in commit hash
1c66dea52380bffcd58966ae8a750590a704c95a
Fix build for Alloy integration changes
Simplify build sources - don't need to specify subdirectory
Merge pull request #4 from TeamAmalgam/amalgam-alloy-integration

Integration with Alloy