[scripts] Add features to MascaretGeoFile and Section (1D) classes + code-style correction & docstring

See merge request !115

Corrections in the vnv notebook example to the new name of some function
of Section class and one fix to detect the right geometric format for
MascaretGeoFile class

+ upate of NEWS.txt for modifications of Mascaret file Python Classes

Add a method to MascaretGeoFile class to generate a GIS file with the
format of PreCourlis (specific attributes to describe geometry and
other Mascaret-Courlis informations)

Adaptations to the new name for the definition of sediment layers in
Section class

Change the name of the original function for adding sediment layer to a
MascaretFile

Add an attribute to the class (topo-bath) to Section class to store
minor/major bed limit in profiles

Some corrections of syntax and add docstring

Add reading of topo-bath information which is given by a string in the
geometry file for each points of each profile ("B" stand for bathymetry
and "T" for topography). This information is used to mark the limits
between minor and major bed.

Add reading Courlis geometry files (geoC and georefC)

Add an option to the class to activate or desactivate loading of the
file

+ some syntax corrections

Enables also the Winterwerp hindered formula (there was a CALL PLANTE
without any explanations)

[fix] when the keyword NEXT COMPUTATION is suppressed in the dictionnary, it has to be suppressed in dependencies too

- The keyword MORPHOLOGICAL FACTOR ON BED EVOLUTION is replaced by
MORPHOLOGICAL FACTOR and the keyword MORPHOLOGICAL FACTOR ON TIME
SCALE is removed.
As we have only one keyword, the name of the variable is for simplicity
MOFAC. It replaces MOFAC_BED (variable used for MORPHOLOGICAL FACTOR ON
BED EVOLUTION) everywhere in the code.
- New keyword OUTPUT TIME FOR MORPHOLOGICAL FACTOR
- Update user doc

- Up to now the coefficients were truncated
- Update reference files (it only concerns cases with wave effect)
- Light relax of epsilon for Bailard formula
- Update user doc with correct coefficients
- Reported by N.Durand

 - To be coherent with what is done for erosion if h<hmin
 - Update some ref files
 - Update user doc, including some missing information

[feature #778][gaia] Apsley and Stansby formulation for slope effect and sliding [R. Kopmann]

Closes #778

See merge request !109

- new option for slope effect, available for all bedload threshold
formulas
- new option for sediment slide
- keyword SEDIMENT SLIDE: from logical to integer
- new test case for sliding
- update user doc
- modification of figures for yen example and corresponding validation
doc
- close issue #778

The values of some blocks are not written in modified PREDES_GAIA

- Keywords are: FLOCCULATION FORMULA and HINDERED SETTLING FORMULA.
- The hindered settling formula was hardcoded and set to 1.

Bug fixed by R.Kopmann

CVSM output period is now coherent with the value in the steering file
for output of specified nodes.
Bug fixed by R. Kopmann.

in 3D for heat exchange with atmosphere model
+ adding various formulae available for atmospheric radiation (user manual)
after jurjendejong remark on the forum

keyword (in particular for 3D), after jurjendejong remark on the forum

in a comment (octas or tenths)
After jurjendejong questions on the forum

(octas or tenths)
After jurjendejong questions on the forum

(octas or tenths)
After jurjendejong questions on the forum

- Missing information about keyword CLASSES IMPOSED SOLID DISCHARGES
  DISTRIBUTION
- Wrong description of cli file to impose solid discharge through
  keyword
- Better indentation for subroutines used to prescribe solid discharge
- Right units for bedload discharge in fortran (only comments) and doc