Better support for CVC4

- Cast integer literals to reals if returned in a model for a
  real-valued term or variable
- Fail if using precise quantifier elimination or switching to it
Merge pull request #172 from chsticksel/develop

Better support for CVC4
Warn if using inductive step without BMC
Merge pull request #173 from chsticksel/develop

Warn if using inductive step without BMC
Removed var op var candidate terms from init/trans.
Omit unsat core option to solver if not needed
Merge pull request #175 from chsticksel/develop

Omit unsat core option to solver if not needed
Merge pull request #176 from chsticksel/inv-gen

Map and guards to instantiate vars in called nodes
Call aclocal from autogen.sh, update ZeroMQ
Merge pull request #177 from chsticksel/develop

Call aclocal from autogen.sh, update ZeroMQ
Only path compression with equality by default
Merge pull request #178 from chsticksel/develop

Only path compression with equality by default
Merge remote-tracking branch 'upstream/inv-gen' into invGen-no-explicit
Squashed 'ocamlczmq/' changes from 2ef98ae..582d025

582d025 Fixes for upgrading to CZMQ 2.2.0
4d504b2 Call aclocal from autogen.sh
9e6d8a3 Merge branch 'master' of github.com:chsticksel/ocamlczmq
596d381 Updated CZMQ to version 2.2.0
5bfa902 Squashed 'czmq/' changes from 8c6a6bc..b22dd58
78c4460 Updated ZeroMQ to version 3.2.4
af71eab Squashed 'zeromq/' changes from fd02f84..a52e1d6
4c0ce5c Removed commented lines
2aa6c49 Merge branch 'master' of github.com:chsticksel/ocamlczmq
b35f9e0 Removed autogenerated file

git-subtree-dir: ocamlczmq
git-subtree-split: 582d025e3aea12cd4718c74482a48aa49a91f867
Merge commit '0e0586ecfb868fcb086e7bfa01d01ac1761d5a6a' into develop
Merge pull request #179 from chsticksel/develop

Fix for updated ZeroMQ interface
Merge pull request #180 from chsticksel/inv-gen

Refer to calling node in instantiation map
Integrating guarding in term instantiation
Merge remote-tracking branch 'upstream/inv-gen' into invGen-no-explicit
Buggy commit, two-state invgen unsound (one-state might be also).