Created by: davido
Summary: Closes issue #200 (closed).
get_base_path() works only in build file context. Make it works also in include context.
Introduce new method: get_dir_name() to retrieve dirname for the current build or include file.
Test Plan:
- Add buildfile.includes = //bucklets.defs line to .buckconfig
- Put this line: d = get_dir_name() in bucklets.defs
- Verify that the root directory of project is returned