Context and description

This PR consists in bringing the latest development into master. They consist of the following:

class enum ELTYPE member names have been modified from EL_NAME to NAME
override keyword have been added for flow module
flow module and part of tbox module have been documented
Various refactoring for the following classes:
- Pt
- Link
- MshDeformation
- flow::Wake
- flow::Kutta
CMakeLists have been updated so that each module finds its own required packages. This is a first implementation but it can be further improved
nogui options has been added to some fdtd module testcase to supress plot output when using ctest. This is a temporary solution
Minor changes and cleaning

[Failed] Update master