renamed most gmsh* classes

Plugin/Triangulate.cpp
Post/PView.cpp
Post/PViewDataRemote.h : Change for compilation on SunOS

CMakeLists.txt : Change mkl libraries on windows

change Spline to BSpline in GSHHS plugin (I hoped MinStraitsFactor Option would allow to use Spline but it's not the case...)

added GModel::getMeshElementByTag (uses a dynamically created cache, like
what we do for mesh vertices)

also transfer vector arrays

(we should design a small container atop the va to store the additional
info we need to transfer: min/max, bbox, timeval)

send/receive vertex array over socket ok