Integration of Chaco into Gmsh

contrib/Chaco/misc/countup_mesh.c

contrib/Chaco/misc/sequence.c

contrib/Chaco/misc/simple_part.c

contrib/Chaco/misc/time_kernels.c

contrib/Chaco/optimize/opt2d.c

contrib/Chaco/optimize/opt3d.c

contrib/Chaco/submain/balance.c

contrib/Chaco/submain/divide.c

contrib/Chaco/submain/submain.c

contrib/Chaco/util/affirm.c

contrib/Chaco/util/bail.c

contrib/Chaco/util/checkpnt.c

contrib/Chaco/util/doubleout.c

contrib/Chaco/util/mergesort.c

contrib/Chaco/util/smalloc.c

contrib/Chaco/util/strout.c