templates: new default for zapp.yaml help->args

The previous default for help->args was a pair of empty strings. For the
most part, this feature is not used and just creates extra
work/annoyance when creating new apps. Every time I create an app, I
need to change the help->args to []. That's the default now.
contrib: add jenkins build artifacts
Merge pull request #201 from larsbutler/ci-scripts

contrib: add jenkins build artifacts
debian/changelog: release version 0.3
Merge pull request #198 from larsbutler/deb-pkg-0.3

debian/changelog: release version 0.3
Merge pull request #199 from larsbutler/fix-zapp-yaml-default-help

templates: new default for zapp.yaml help->args
Rename zapp.yaml templates with `python-` prefix

This is the first step in making project templates explicit. Python-type
templates are still the default, but this begins making room for
distinction. For example, a C-based project template would be the next
logical one to build.
util: initial creation of util module

Includes the class "AtomicFileCreator". This class is intended for
atomically creating groups of files/directories, and rolling back
(deleting) if a problem is encountered, such as a file already existing.

This is useful for gracefully bootstrapping projects, and aborting (and
subsequently cleaning up) and avoiding overwriting existing files.
zapptemplate: initial project template code

This is meant to abstract away project file creation to allow for the
addition of more project templates.

Move `render_zapp_yaml` function from `zpm` to zapptemplate module.
setup.py: reformat deps list
setup.py: add `tox` to dependencies

This will be needed for python project bundling.
commands: add `--template` flag to `zpm new`

This includes the default template of `python`. Functionally, nothing
changes. `python` is the default (and only template).
templates: add project_type to zapp.yaml templates
zpm new: pass template arg to `create_project`
zpm: use zapptemplate to create proj template

This removes a lot of the complexity from the `zpm` module and relies
instead on the `zapptemplate` module for doing most of the work in
creating zapp.yaml and other project files.

This also integrates the `zpm new --template <template>` switch in the
project creation code.

Tests are modified to reflect this change. Some obsolete tests are
deleted.
Add project type-specific bundling (python)

This change adds an extensible but simple framework for bundling
specific types of projects. The default and only bundler implemented
currently is `python`. (This was implicitly true anyway before, so now
it's explicit.)

Includes adding a `--refresh-deps` option to `zpm bundle`.
For the python project bundling template, if --refresh-deps/-r flag is
`True` we recreate the tox-managed venv from which we bundle 3rd party
python dependencies.
zapptemplate: add TEMPLATE_DIR constant
zapptemplate: move tox.ini template to constant
Add tests for `zapptemplate` module.
zpm: fix bundling so that cwd does not matter