Close #506 Add test for RSS feed parser

Add a test that pulls different RSS feed attributes such as title,
speaker, etc. and compares it to a JSON file with the expected results.

test_get_presentations() checks attributes' title, speaker, level,
status, time, event, and room to see if they contain correct values.
Mark RSS feed parser test as expected to fail

This test will be run but no traceback will be reported when it fails.
Instead, terminal reporting will list it as "expected to fail".

Related to #555

http://pytest.org/latest/skipping.html#xfail
Fix formatting

E302: expected 2 blank lines, found 1
Redesign of the Settings List

Make the interface a lot less complicated and confusing. There
are no configuration options in the plugins anymore. It is
simply a list of all the plugins installed. The list starts
fully expanded, but sections may be minimized. When a plugin
is clicked, further details are displayed under the list.

Close #535
Related to issue #411
Merge branch 'plugins' of https://github.com/miakilborn/freeseer into plugins