Additions for Add interpolation areas

See merge request !11

Add interpolation areas

See merge request !8

Georeferencing

See merge request !10

Runs tests on gitlab CI with multiple QGIS versions

See merge request !9

Add an option to interpolate profiles

See merge request !3

Fix the import of georef file : long abscissae

See merge request !2

Add an option to interpolate profiles (lines ou points) to use or not
extreme points of each profiles as constraint lines for the
interpolation

Fix the import of georef file : long abscissae 
An attribute of Mascaret Class is used to get longitudinal abscissae at
the import. This allow to keep the same abscissae in the PreCourlis data
model.