stricter similar-atoms function
make get-mapping uses similar-atoms
strengthen type constraints
Tighetn the allowed variable values
allowed unordered-link, enforce structural match on all nodes/links
changed similar-1-to-n to similar-n-to-nm to fix a bug
instead of selecting first mapping, check all mapping to see which one has name matches
work around for matching node, where returned result is not list of lists
added new version of cartesian-product that works better with lists
fixes problem of not combining results correctly
added missing documentation formatting
fixed buggy commit
fixes incorrect handling of #f
potentially allow self-grounding of variables.

These are a set of changes pertaining to the discussion in bug #1092
If the NO_SELF_GROUNDING token is not set, then the self-grounding of
variables should work.  I think. Its not well-tested, and could lead
to trouble.
Merge pull request #1100 from linas/freaky

Preparation for allowing the self-grounding of variables
Merge pull request #1098 from williampma/SuRealEdit2

SuReal: changed get-mapping
Remove redundant Vagrant procedure
Merge pull request #1103 from cosmoharrigan/vagrant

Remove redundant Vagrant procedure