ert test enhancements

- fix: s/go-test-verbose-mode/go-test-verbose/

- support for testing within emacs (ala M-x ert)

- add test/go_test.go for use with tests

- ert test go-test-get-current-file

- ert test go-test-get-current-test
Workaround go test -file

While 'go test' has a '-file' argument, it isn't actually supported.
See the source for src/cmd/go/test.go:
  "testFiles        []string   // -file flag(s)  TODO: not respected"

Workaround this by generating a regex for tests in the current file
and pass to 'go test' via the '-run' flag.
Merge pull request #5 from dougm/current-file

Workaround go test -file