Peter M. Groen / oletools

Replace #print(...) with DEBUG_FLAG and conditional print(...)

This is not necessary in python3

The python sniffer would find "i" as delimiter in text or "<" in xml. We
prefer an error over misinterpretation.

Also, try all delimiters, not just a second one.

Rename one constant (added CSV_)

- move imports further up
- simplify code for oletools import hack
- make a few variable names longer

- disable pylint-whitespace-check from FIELD_BLACKLIST
- shortend most all lines to max 79 chars (except pylint: disable-*)
- moved imports further up
- re-wrap a few lines
- add missing doc strings
- add/remove whitespace
- remove old commented debug-log/print statements

Fixes

Trying to get rid of all those ResourceWarnings that python3 shows during
unittests

Looking for reason for ResourceWarning abount unclosed BufferedReader, but
this was not the cause...

All development and testing has been done with a singe, very simple,
self-made sample. On the road, found lots of other potential ways to
include data from external sources.

Often you want to know size of a stream or re-set it to start, both of
which are not provided by ZipExtFile (result of ZipFile.open). Implement
both in own class.