fixed a few bugs in processing.tf and added class plottf to imaging, not fully test yet but works so far on small time series (less than 86400 data points)
Merge branch 'master' of https://github.com/geophysics/mtpy
renamed plottf to plotspectrogram, and removed empyt file spectrogram
setting Z object directly within Edi object -updated/corrected the assertation of correct format for the Z array

Signed-off-by: LK <LK@uni>
allow writing of edi files with a Tipper attribute set to zero (esp. required for synthetic cases) - allow Edi.rotate() with scalra angle given

Signed-off-by: LK <LK@uni>
adding a package to deal with Winglink output files, put it in utils
added residual pseudo section plot to occam2d
distortion.py: find_distortion now operates on full z array

Signed-off-by: LK <LK@uni>
Merge branch 'master' of github.com:geophysics/mtpy
distortion.py: corrected last approach - was def. wrong - focussing on 1D part, if possible!

Signed-off-by: LK <LK@uni>
fixed bug in mtplottools if there is no z_err input, error in determinant is set to ones, added function to discretize color maps in mtcolors
corrected errors in the reading of spectra-type edi files - problems with underscores in tippererr removed

Signed-off-by: LK <LK@uni>
Merge branch 'master' of github.com:geophysics/mtpy
edi.py : reading spectra data - corrected missing blank space between concatenated lines of spectra entries

Signed-off-by: LK <LK@uni>
fixed bug in plotresponse when plotting skew angle
fixed bug in plotresponse when plotting phase tensor, size is now correct
fixed bug in plotresponse when plotting xlabels are now correct
fixed bug in plotnresponses when plotting phase tensors, size is now correct
changed the ResidualPhaseTensor to I-pt1^-1*pt1 and added attribute residual_pt which is a PhaseTensor object so you can calculate skew, azimuth, etc.
changed tipper_err (imaging convention) to tippererr (core convention)

Signed-off-by: LK <LK@uni>