add one speed test ...

machine dependant, to get an idea...
gf : target_shape_t. change size_t to int

- to avoid narrowing pbs.
- otherwise {n,n}, with n int does not work, which is crazy.
small change in clang-format config.
add trace for ImmutableMatrix
Merge branch 'master' of github.com:TRIQS/triqs
correction of windowing near the edges of the mesh for half_bins
Fix #51

- The kind() method of mesh should return a char,
like the parameter of the constructor of mesh,
not the C++ corresponding int.
- otherwise, the reduction - construction is broken
and by extension all pickling and then all mpi constructions.
Fix for clang 1y with gcc lib

- add a workaround for a gcc issue in fisrt_include.
- --> make sure that the first include is :
either a triqs lib
or first_include
Merge remote-tracking branch 'triqs_lib/master'