Use existing __main__ namespace to execute scripts (closes GH-331)

See merge request !7

Only avoid SetPropogatingDict in the builtin shell in Python 2

The issues with using a custom dict subclass to eval/exec are fixed in
Python 3. Without this, local functions in the shell cannot access global
variables (for instance, inside of list comprehensions).

See the discussion on issues #166 and #103.

Add support for scrolling sidebar panes with j/k

This adds support for scrolling the variable, stack, and breakpoint
panes with the 'j' and 'k' keys. This functionality is disabled by
default, and can be enabled with a new config option in the config
dialog.

Fix ci

See merge request !6

Drop requests from requirements.dev*.txt

Adapt .travis.yml to use correct req.txt file for Py2.6

Make Flake8 3.6 happy

See merge request !5

Upgrade pytest-mock in requirements.dev.txt

See merge request !4

Add ability to control pudb from a separate tty

Add Pytest/JUnit/Gitlab integration, Py37 CI

See merge request !3