FIX: backcompat ICA
Merge pull request #1620 from dengemann/ica_copmat_bw

FIX: backcompat ICA
make nose assert_true optional import
Merge pull request #1621 from maedoc/fixes-nose

make nose assert_true optional import
Make fit_sphere_to_headshape work in more cases

 - Add flag to select which digitization points to use in
   `fit_sphere_to_headshape`.
 - Make `make_eeg_layout` still work even if no digitization points
   are present. Generate a warning though.
Tweak error message
`fit_sphere_to_headshape` all points in same plane

It's common for the data to only define the nasion and auriculars. These
landmarks are all on the same plane. When fitting a sphere through
these, the z-position of this sphere is essentially undefined. This
patch forces the z-position of the sphere to be 0 in this case.

Also added some tests to verify this function behaves well.
not zero, but point mean
Revert "not zero, but point mean"

This reverts commit b8cc9b9fc8e2c66a9d43ecae37b9a8ab1e538ed7.
Revert "`fit_sphere_to_headshape` all points in same plane"

This reverts commit b2ba148dc6aa9663cbfbb1edc94a5d2c96e0db83.
Added tests, kinds now as tuple
Don't display warning during tests
Make user specify origin_head
Merged 3D to 2D mapping of electrode positions

There was a duplication of code for mapping 3D electrode positions
to a 2D space. Both the `_auto_topomap_coords` and
`make_eeg_layout` functions had their own implementation.
updated docstrings
Implement option 2

Raise warning when no digitization points are present
and no origin_head is specified.

Add origin_head parameter to topomaps.
Add separate testcase for _auto_topomap_coords
Merge branch 'eeg-layout-fix' of github.com:wmvanvliet/mne-python into eeg-layout-fix