GitLab

in addition to the default camelCase function names, add snake case aliases in the Python and Julia API, as this is the recommended style in these languages

make edge identifiers size_t + fix arguments of mesh/getEdgeNumber + add mesh/getFaceNumber (these should be renamed...)

- CharacteristicLength -> MeshSize, geometry Lines->Curves

initializing the api now sets General.Terminal=1 (to print messages by default) and General.AbortOnError=2 (to throw an exception as soon as an error happens) - cf. #1043

- add "geo" versions of add/RemovePhysicalGroup in anticipation of move of "master" physical group definition in GModel (we will need to keep the built-in kernel defintion as well, since built-in CAD operations track physicals)
- more explicit mentions of CAD kernel in api docs