Add support for go and defer statement checking.

Needs bugfix in go/types.
Update GH-30.
Add unit tests.
Add drone.io status badge.
Don't use Println to print error strings, silly.
Minor test cleanups
More sophisticated testing.
Simplify comment parsing
Test for checking of go and defer statements.

Now that go/types has been updated it works.
Show default ignore string in -help.
update to new importer API
Add introduction to vim plugin
Merge pull request #31 from mattn/vim

Add introduction to vim plugin
Report ignored return values from recover().
Test with Travis CI
Add the travis badge.
Only special-case the builtin recover() in case some nut redefines it.

As per @dominikh's suggestion.
Updated for latest go/types api.

Fixes #33
Add some preliminary cgo support.

Updates #16.
Update to new go/types API.

Fixes #34