Freebsd10 memlimit check and overlength-strings error workaround.

I had two problems on FreeBSD 10. First, a compile fail with an overlength string error. Just to get it working, I added a `-Wno-overlength-strings` option to get it to compile. This probably is a code smell and needs to be looked at in a different way, that particular compile error was:

    ./util/test/Bits_test.c: In function 'Bits_test_main':
    ./util/test/Bits_test.c:36:5: error: string length '4263' is greater than the length '4095' ISO C99 compilers are required to support [-Werror=overlength-strings]
    cc1: all warnings being treated as errors

The second problem was the Security check for memory-restriction-- it was attempting to double infinity that caused `cjdroute` to abort on start when it finds it isn't limiting itself.

I have built both with `gcc47` and `clang` and things "worked." I don't have an active connection to Hyperboria so I couldn't test any further than that.

Similar check was already added in #542, seems like @cjdelisle forgot to merge it into master.