average option for plot_evoked_topomap
doc
improve doc and code
typos
update whatsnew
address discussion and add tests
Merge pull request #1602 from dengemann/average_topomap

ENH: average option for plot_evoked_topomap
better doc for permutation_cluster_test
FIX: Fix raw plotting
Merge pull request #1606 from Eric89GXL/fix-filtfilt

FIX: Fix raw plotting
FIX: scipy >= 0.11 needed for coreg test
Merge pull request #1607 from mluessi/fix_scipy_version_coreg_test

FIX: scipy >= 0.11 needed for coreg test
add svg option and improve scaling