Merge branch 'release/5.1.0-beta1'

This release adds :
  - the mmg2d application and library (for bidimensional mesh generation and isotropic/anisotropic mesh adaptation);
  - the anisotropic mesh adaptation for mmg3d and mmgs;
  - the mmgs library (API + mmgslib function);
  - the mmg3dls library function corresponding to the -ls option of mmg3d (allow to discretize an implicit surface);
  - manpages for the mmg2d, mmgs and mmg3d application (available in the doc/man directory);

It modifies the mmg3d library API:
  - the API functions are now prefixed by MMG3D instead of MMG5;
  - the 'MMG3D_Init_mesh' and 'MMG3D_Free_all' functions takes now a variable number of arguments. Please, refers to the documentation to see how to call it.

.gitignore

@@ -14,10 +14,15 @@ doc/doxygen/man
 
 lib
 
-libexamples/mmg3d/example0/example0_a/mesh.*
-libexamples/mmg3d/example0/example0_b/mesh.*
-libexamples/mmg3d/example1/result0.*
-libexamples/mmg3d/example2/2spheres_*
+libexamples/*/*/mainTESTADJA.c
+libexamples/*/*/*/mesh.*
+libexamples/*/*/result0.*
+libexamples/*/*/2spheres_*
+libexamples/*/*/*.o*
+libexamples/*/*/mesh.*
+libexamples/*/*/cube.3d.*
+libexamples/*/*/cube.s.*
+libexamples/*/*/result.*
 
 ci_tests