Add project level settings to allow running go fmt or goimports on save.

The goimports option may be an easy replacement for the import optimizations option.  It does require that goimports already exists in the system path.  This isn't normally a problem if the system path includes $GOPATH/bin and one runs the following command.

    go get code.google.com/p/go.tools/cmd/goimports

The already existing code that ensured the file ended with a line feed has been removed because both gofmt and goimports will do that for you.

This pull request changes the project settings dialog to look like this:
![go_settings](https://cloud.githubusercontent.com/assets/1229385/4177366/c320c7f2-363b-11e4-809c-88abcc3acbe7.png)

The default setting is to run go fmt on save.