Modem: model generation - started setup with high density central grid

Signed-off-by: LK <LK@uni>
modem MakeModel: central grid regular, outer grid extending exponentially - automated calculation - outlying stations have to be excluded before running the script

Signed-off-by: LK <LK@uni>
modem MakeModel: better visualisation - info on blocks given is consistent - depth padding adjusted to reasonable measures (~3 times model depth)

Signed-off-by: LK <LK@uni>
modem MakeModel: added option for rotation to adapt geometry to potential 2D structures. New X axis will be along strike direction. Station locations in data file have to be changed accordingly

Signed-off-by: LK <LK@uni>
modem: added makeData script...very static at the moent, but oes the trick - no rotation yet - has to be combined with the makemodel later

Signed-off-by: LK <LK@uni>
modem Data file generation: periods in floating point format, number of different periods calculated....output works!
modemMakeData...corrected for all components

Signed-off-by: LK <LK@uni>
makeModemData calculating correct number of periods now (rounding errors before)

Signed-off-by: LK <LK@uni>
utils: built script for merging period lists

Signed-off-by: LK <LK@uni>
Merge branch 'master' into lk.modem
Modem - included functionality for merging periods into the MakeData script - consistent rounding of period values to 5 digits introduced

Signed-off-by: LK <LK@uni>
changed all lst to list in imaging for clarity
fixed bug in occam1d with plotting and added flexibility with startup file. Added flexibility with writing WS_initial file
fixed bug in mtplottools in get_period, now _freq is the only local parameter to avoid mixing of freq and period
fixed bug in Z.z.set_res_phase line 567, changed array to single value as needed by propogate_error_polar2rect
added ability to plot impedances in ws3dinv
fixed documentation example in imaging files
Merge branch 'master' of https://github.com/geophysics/mtpy into new_occam
building on Data object