Specify dependencies more fully

[pjvandehaar]

When installing on a fresh Ubuntu 16.10 server, I had to do sudo apt-get install make cmake java-common default-jre libssl1.0.0 g++ libz-dev libncurses5-dev.

scripts/check_requirements.sh:

• informed me about make java-common default-jre
• suggested libssl0.9.8 which is no longer available (and libssl1.0.0 passes the tests anyways)
• complained about missing /usr/local/gotcloud/test/umake even though I have ./gotcloud/test/umake
• missed cmake g++ libz-dev libncurses5-dev

[pjvandehaar]

TODO:

• [ ] add cmake g++ libz-dev libncurses5-dev to check_requirements.sh
• [ ] allow any ssl ≥0.9.8 (and deal with fallout later)
• [ ] check for either of ../test/ or /usr/local/gotcloud/test.