Merge libgmxana into libgromacs.

- Move contents of src/tools/ into src/gromacs/gmxana/, except for
  g_tune_pme.c and g_pme_error.c.
- Delete unused src/tools/g_membed.c.
- Adjust the build system accordingly, removing references to gmxana.
- Merge contents of libgmxana.pc into libgromacs.pc and remove the
  former.
- Move src/gromacs/legacyheaders/gmx_ana.h into src/gromacs/gmxana/ and
  adjust files that include it accordingly.  Removed a few unnecessary
  inclusions of this header.  Don't install it, as it doesn't do much
  good.
- Merge src/contrib/g_sdf.c into src/contrib/gmx_sdf.c to make it
  independent of gmx_ana.h.  Remove gmx_sdf() from gmx_ana.h.

Closes #1013.

Change-Id: I34ba52fc938823833103123c8ada06d169abf7de