Fix msh output in FM and MM for Abaqus.

This commit duplicates 298615ed2ff6d040df6ed93fc2cdfae3502b93c2, but now for Abaqus output, i.e.:
When writing a mesh with elements of different dimensions (several of:
0D, 1D, 2D or 3D), the elements of a given dimension were always
numbered from 1, and therefore several elements could have the same id,
which is not allowed. The elements are now numbered contiguously from 1.
Fix Abaqus output in -FM and -MM.

A header line "*Part, name=tess" and a foot line "*End Part" have been
added to the .inp file.
Merge branch 'devel' of https://github.com/rquey/neper into devel

Conflicts:
	VERSIONS
	doc/texinfo/version.texi
	src/CMakeLists.txt