Implement "..." wildcard for packages and paths.

Fixes #58.

Signed-off-by: David Symonds <dsymonds@golang.org>
Complain about exported functions/methods returning unexported types.
Allow one underscore between digits.

Fixes #47

Signed-off-by: David Symonds <dsymonds@golang.org>
automatically add test package if it does exists
read the content of files only once
separat packages by directory
always split test packages