Commit this version of the documentation (let's say we reached a small
milestone). But documentation should not be checked in too often, and should
remain in a stable (i.e., clean) state, even if it is incomplete.
Directory structure is dev/doxy for the temporary files (not checked in, they
are the product of make_doc.sh script, generated simply by doing:
export HDSTL_ROOT=.../SOC/2007/geometry/libs/hdstl
and adding $HDSTL_ROOT/tools to your path, then in the directory dev/hds_concepts,
simply "make_doc.sh *.hpp").