v0.1.2, 2015-02-11 -- Pull files from Didel

General changes:

* ~/.netrc support for authentication
* `pull:save` and `pull` actions added by @tsalmon (#4)
  The first one lets you choose a path where it'll download all files from all
  the courses you follow in one directory that can later be updated with the
  second command. `pull:save` saves the path so that `pull` doesn’t need it,
  it’ll pull in the previously saved path.

Minor changes

* `^C` properly handled by the CLI module

Python API:

* `DidelConfig#get_credentials` added, which returns a pair of `username` and
  `password` for the current configuration, or fallback on `~/.netrc` if it
  can.

* `Session#logout` removed. It’s not necessary because cookies are not saved
  between sessions so just deleting the session object disconnects you

* `logged` boolean attribute added on `Student`. It'll be `True` if the student
  was successfully logged in.
* `Student#synchronize_docs` method added (#4), it fetches all documents from
  all courses followed by the user and download them in the given path. It
  doesn't re-download a document if it already exist locally.

* New module: `didel.exceptions`, provides `DidelLoginRequired` which is raised
  by the `Student` methods which require a loggued session and
  `DidelServerError` which is raised by `Session` objects in some methods to
  signal a server-side error.


v0.1.1, 2015-01-31 -- Python 2.6 support

General changes:

* Python 2.6 and 3.x support fixed
* Persistent cookies (broken) support removed

Python API:

* Internal exceptions are now of the class `DidelError` instead of `Exception`
* `DidelEntity#fetch` method now properly handle objects with no `path`
* Some classes are imported in `__init__`, making them available with a shorter
  form:
      from didel import Student
  instead of:
      from didel.student import Student
  These classes are: `Course`, `CourseAssignment`, `CourseAssignments`,
  `Session`, and `Student`.
* `Student#login`’s `save` optional argument removed
* `Session#save` and `Session#load` removed

Command line:

* `courses:show <code>` added to open a course's page in the browser
* `courses:alias <alias> <code>` added. It allows one to set an alias for each
  course:
    $ didel courses:show M2T2INFOEMB       # course code, hard to remember
    blah blah
    $ didel courses:show emb               # this one doesn't exist
    <error>
    $ didel courses:alias emb M2T2INFOEMB  # alias it to a shorter name
    $ didel courses:show emb               # easier to remember
    blah blah
  Aliases are stored in the configuration file, which makes them easy to edit
  with your text editor.

v0.1.0, 2014-10-13 -- Initial release

* Student connection
* Course info
* Enroll/Unenroll from a course
* Assignments list
* Submit an assigment
* Command-line interface

Known bugs:

* Cookies are not saved between sessions
