Add jedi:create-flat-imenu-index
Make imenu-create-index-function configurable

by adding jedi:imenu-create-index-function
Update changelog
Define local_name and use it instead of full_name
Fix: local_name did not work with level > 2
Require Jedi >= 0.6 now
Add tests for defined_names in test_jediepcserver.py
Install nose in Makefile
Use py.test instead of nosetests
Use dev version of Jedi in testing
Add $USE_JEDI_DEV envvar
Use tox to run tests on Python side
Fix .travis.yml to use tox
Refactor Makefile
Add fixture for jedi cache
Rename: s/create-imenu-index/create-nested-imenu-index/g
Merge branch 'flat-imenu'

New option `jedi:imenu-create-index-function` is added to switch
nested and flat style for imenu index.  Other changes are
introduced also:

1. Test for server script is run by py.test in tox.

   This is because I need developmental version to make test pass,
   but I don't want to install it in the user's env/ directory.

2. `install-jedi-dev` make target is added.  This makes easier for
   user to try developmental version of Jedi.

3. The old function `jedi:create-imenu-index` is renamed to
   `jedi:create-nested-imenu-index`.

fixes #53 and #62
Bump to 0.1.2alpha3