Revert "Making plugin inclusion relative to the calling module (issue #22)."

This reverts commit 821033927f0d0e4f6afdb538d840df7ae7563287.
Making plugins load relative to the calling module (issue #22).
Merge branch 'issue_22' into 0.3
Bumping package version to '0.3.1'.
Merge branch '0.3'