Add a STINGER_MAX_MEMSIZE environment variable to control initial allocation.

Eating all memory is not conducive to laptop-based development, so add a
method to limit the maximum memory size.  The parsing is rudimentary but
should work.  Also bump the default number of vertices a bit and shrink
to fit more slowly.
CMake-ify the STINGER default size in stinger_defs.h and stinger_names.h.

Should permit easier re-sizing for smaller machines.
Support STINGER_MAX_MEMSIZE in the shared memory allocation.

I hadn't noticed that shared allocation is entirely separate...
Update some of the size-tracking internals in simple_communities.

Simply targeting a maximum community size may work now.  Truly managing
the community size limit on the fly needs more thought.
Add STINGER_MAX_MEMSIZE to the README example.
Merge branch 'master' of https://github.com/robmccoll/stinger
Fix long-standing semantic bug in graph-el allocation.

Allocating a graph shouldn't produce one with a garbage (uninitialized)
but "full" (ne == ne_orig) edge list.  Caused simple_communities to
crash with initial computation because the ne wasn't reset to zero.
Add stinger_max_total_edges() for a fast upper bound.  Plus clean-up.

The number of edges is bound by the number of slots being used for them,
so return that as an upper bound.  Simple arithmetic rather than
a (parallel, now) loop.

Also use stinger_edges_up_to to implement stinger_total_edges, and drop
a parallel clause in stinger_edges_up_to.
Start support for re-running static community detection.

This is triggering asserts related to weight conservation within community().
Add a mention of CMAKE_BUILD_TYPE to README.md.
Fix long-standing uninit. memory bug in simple_communities.

The diagonal hadn't been initialized to zero.  This update may have a
spare initialization, but that's not important.
Add *~ to .gitignore.
Add a simple sparse matrix - sparse vector test client.

This is to be expanded later and possibly merged into STINGER itself.
Oh, yes, actually save the new index in spmspv...
Include a trivial OpenMP spmspv...

Note that *both* implementations have massive bugs...
In spmspv_test, save the x pattern in a dense output vector.

Quick hack.
spmspv_test: Fix one obvious mistake in the update.
spmspv_test: Actually allocate enough space for the dense vector.
spmspv_test: simplify / fixish the cwise relative error.

OpenMP version still produces the wrong answer, which isn't bad in this
context.
Fix forgotten initialization.  Now the OpenMP example works.