Remove dead code, unneeded casts, add annotations

* Dead code is what it says: imports that were not used and local variable initializers that were not needed
* Unneeded casts is self-explanatory
* Added `unchecked` annotations where types were not enforceable by the compiler
* Added `unused` annotations for items that the editor was not able to prove are in use
Remove unused virtualenv constant
Merge pull request #4 from mdaniel/java-code-cleanup

Remove dead code, unneeded casts and add annotations
Set url to pyleus.org in setup.py
Add workers tip in tutorial.rst
YAML syntax doc page
Fix typos in docs
Merge pull request #20 from patricklucas/fix_typos_in_docs

Fix typos in docs
Merge pull request #19 from patricklucas/set_url_to_pyleus.org

Set url to pyleus.org in setup.py
Exclude superfluous LICENSE from jar

Exclude META-INF/LICENSE from jar, since a directory named
'license/' is also created, and this causes problems on systems
with case-insensitive filesystems. The origin of these files is
unclear; perhaps this plugin overlays the META-INF directories of
all dependencies. LICENSE and LICENSE.txt (which will remain) are
identical copies of the Apache 2.0 license, so there is no legal
issue at stake.

Closes #22
Refs #17
Rename --nimbus-ip option to --nimbus

Closes #2
Reword --nimbus help text
Merge pull request #23 from patricklucas/fix_pyleus_build_on_case_insensitive_fs

Exclude superfluous LICENSE from jar
Fix base jar installation

Previously, pyleus-base.jar was installed to sys.prefix + '/share/pyleus/
pyleus-base.jar', and this worked fine when Pyleus was installed in a
virtualenv or via an fpm-created deb. In the former case, the jar was
installed to $VIRTUAL_ENV/share/pyleus/pyleus-base.jar, and in the latter,
it made its way to /usr/share/pyleus/pyleus-base.jar.

However, if a user just ran 'pip install pyleus' on their system, the jar
would actually be installed to /usr/local/share/pyleus/pyleus-base.jar,
even though sys.prefix was just '/usr' when pyleus was executed.

Pyleus would thus look in /usr/share/pyleus and fail when it couldn't find
the base jar.

This change uses the seemingly preferred method of including the jar
within the package itself, and using the pkg_resources module to construct
its filesystem path.

The build step of removing the base jar from a topology jar (since it is
unneeded and takes up space) required modification as well.

Closes #24
Update .gitignore
Remove copy of base jar during 'make clean'
Merge pull request #25 from patricklucas/rename_nimbus_ip_option_to_nimbus

Rename --nimbus-ip option to --nimbus
Merge pull request #27 from patricklucas/fix_base_jar_installation

Fix base jar installation
Add virtualenv dependency

Closes #21
Merge pull request #28 from patricklucas/add_virtualenv_dependency

Add virtualenv dependency