replace from_list with from_section

[WolfgangFahl]

IMHO the section handling would be improveable by introducing a Section class that keeps track of
the parser_state and configuration settings such as the ignor_line_codes setting. The line numbering could then also be fixed that it has the correct line numbers and not the ones after stripping the newlines.

For a start the interface of from_list needs the parser_state as a second parameter which makes some extra parameters such as line_number superflous. In a next step the combining to a section class, renaming and having only a single parameter would be IMHO an improvement.