Mac builds with Matlab failing in compile of Iris

[ggould-tri]

Starting two nights ago, but masked by other build failures yesterday, all mac builds with matlab began failing during the compilation of the iris external.

Example failures: https://drake-cdash.csail.mit.edu/viewBuildError.php?buildid=331321
Relevant commits listed here: https://drake-jenkins.csail.mit.edu/view/Nightly%20Production/job/mac-clang-nightly-matlab-debug/172/

Typical errors are:
...iris_wrapperPYTHON_wrap.cxx:4793:12: error: explicit specialization of non-template struct 'traits_reserve'
cddlp.c:2954:109: warning: data argument not used by format string [-Wformat-extra-args] if (localdebug) printf("No interior-point is found and thus the standard LP technique will be used.\n", ired);
cddio.c:1948:16: warning: assigning to 'char *' from 'const char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
cddlib.c:116:59: warning: for loop has empty body [-Wempty-body] for (itemp=1; cone->OrderVector[itemp]!=hh; itemp++);
cddlp.c:2954:109: warning: data argument not used by format string [-Wformat-extra-args] if (localdebug) printf("No interior-point is found and thus the standard LP technique will be used.\n", ired);
cddio.c:1948:16: warning: assigning to 'char *' from 'const char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
cddlib.c:116:59: warning: for loop has empty body [-Wempty-body] for (itemp=1; cone->OrderVector[itemp]!=hh; itemp++);
cddlp_f.c:2955:109: warning: data argument not used by format string [-Wformat-extra-args] if (localdebug) printf("No interior-point is found and thus the standard LP technique will be used.\n", ired);
cddio_f.c:1949:16: warning: assigning to 'char *' from 'const char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
cddlib_f.c:117:59: warning: for loop has empty body [-Wempty-body] for (itemp=1; cone->OrderVector[itemp]!=hh; itemp++);

[rdeits]

This is a result of our patched version of pycontainer.swg, which is used by SWIG to wrap std::vector and the like. The version in SWIG has a bug when used with types like Eigen's, so we ship a patched version in swigmake. Unfortunately, that makes us very sensitive to the SWIG version. Specifically, I know that SWIG 3.0.11 is incompatible with that patch, hence rdeits/swigmake#6

Now that we're moving away from drake shipping its own copy of SWIG, we can't rely on an exact version, so this patched pycontainer.swg approach won't work. I'm fine with disabling IRIS in the drake superbuild until I can resolve the situation (possibly by switching IRIS from SWIG to pybind11).

[rdeits]

This will be fixed when rdeits/iris-distro#52 comes in (since it removes the entire SWIG layer from IRIS)