Refix issue #5 (Correct indent after end of block)

The implementation clean up reintroduced a more severe
version of the bug. Plus, the test was slightly deficient
to catch the regression.

Problem
-------
Given two adjacent blocks where the 2nd block has
an equal or smaller indentation level compared to the 1st
block. If the 1st block does not end in a stop statement
it always sucks up the 2nd block.

This changes the meaning of code that already adheres to the
pep8 standard.

Solution
--------
Do not inherit indentation of the previous line if the current line
has less indentation but is valid.