removed static CTX (replaced with singleton)

Common/CommandLine.cpp

Common/Context.h

Common/CreateFile.cpp

Common/Gmsh.cpp

Common/GmshMessage.cpp

Common/Main.cpp

Common/Makefile

Common/OpenFile.cpp

Common/Options.cpp

Common/VertexArray.cpp

Fltk/Draw.cpp

Fltk/GUI.cpp

Fltk/Main.cpp

Fltk/Solvers.cpp

Fltk/aboutWindow.cpp

Fltk/classificationEditor.cpp

Fltk/clippingWindow.cpp

Fltk/colorbarWindow.cpp

Fltk/contextWindow.cpp

Fltk/extraDialogs.cpp