Remove contact in place (without rebuilding list).
Docstring fixes.
Just a list.
Honour import style.
Delegate removal to python. Avoid recreating list.

* Using list.remove means the element is removed
  in-place and no new list is created. This lessens
  the space requirements and may improve speed.
Simplify getContacts.
More docstring fixes.
Raise value error when removing non-existing contact.

Fix #535.
Enable due test.
Remove execute flag.
Wrap long line.
Improve comment.
Wrap most long lines: fix all bad hanging indents.

* Fixes many E501-s; more work needs to be done.
* Fixes all E127-s.
Enable flake8 style check for hanging indents.
Bump flake8 version.
Merge pull request #548 from Renelvon/sane_kbucket

Refactor node/kbucket.
Merge pull request #559 from Renelvon/wrap_long_lines_1

Style fixes: wrap long lines, fix hanging indents, bump flake8
Merge pull request #561 from benemorius/upnp

PortMapper: fix clean_my_mappings not deleting UDP mappings
Rename docs/02 Auctions.md to docs/markets/01 Physical Goods.md
Rename docs/03 P2P-Lending.md to docs/markets/03 P2P Lending.md