empymod/empymod: empymod v1.4.4

[This was meant to be 1.4.3, but due to a setup/pypi/anaconda-issue I had to push it to 1.4.4; so there isn't really a version 1.4.3.]

• Add TE/TM split to diffusive ee-halfspace solution.

• Improve kernel.wavenumber for fullspaces.

• Extended fQWE and fftlog to be able to use the cosine-transform. Now the cosine-transform with the real-part frequency response is used internally if a switch-off response (signal=-1) is required, rather than calculating the switch-on response (with sine-transform and imaginary-part frequency response) and subtracting it from the DC value.

• Bug fixes

• Version of CSEM book.