Merge pull request #2 from jgosmann/upstreamDev

It was a division from the __future__! Still, using 0.5 will make it clearer for people reading the code.
Catch 0.2.0 API calls so as not to break API for now
Renamed spykeplugin script and updated documentation
Override guidata.DataSet.get_title() so option windows have plugin name as title
All plot functions now return the PlotDialog
New methods in PlotDialog for setting background color and replacing plot item colors
Fixed needs_qt decorator so decorated functions can have return values
Updated documentation to include NeuroDebian and mailinglist
Compatibility with older guiqwt versions
Minimum version for guiqwt
Spike sorting quality assessment enhanced: Now possible without prewhitening, mean and covariance can be estimated
Improved documentation consistency concerning Neo objects
Renamed start_plugin.py to startplugin.py for consistency
Change name of startplugin script in setup.py
set_parameters() robust against surplus parameters
Bumped version
Corrected docs for current plugin architecture
PEP 8
Correction in documentation.