Add expansion for python.el to mark a decorator on top of a block

    - added er/mark-python-block-and-decorator
er/mark-python-block-and-decorator: don't keep going up after passing decorator lines
Improve er/mark-python-block-and-decorator
Merge pull request #89 from vmalloc/issue-86

Issue #86: Add expansion for python.el to mark a decorator on top of a block