CBD-2702: Number of fix-ups to support toy Docker builds, etc.

[ceejatec]

• Don't assume VERSION is part of download URL, to allow downloading toy .deb builds from any location
• Fix package dependencies for Mad-Hatter (python-httplib2 out, bzip2 in)
• Add better method for comparing versions
• Remove generator code for older unsupported Server versions (2.x, 3.x)
• Remove historic Dockerfiles for unsupported Server versions and pre- releases
• Use --no-verbose when downloading .deb to make output easier to read