Bug fixes and further standardization.

1. Fixed a few more file endings. 
2. Performance plots were not correct because the ica artifact rejection on raw data was performed in memory rather than on a copy. Setting option "copy=True" fixes this. 
3. Fixed small bug on jumeg_test.py

This will be merged now. Please run the below commands to update your masterfrom your jumeg directory: - 

git checkout master
git pull upstream master