Usability tweaks and many bug fixes

[netj]

Notably:

• Faster deepdive compile
  • replacing HOCON parsing in Scala with pyhocon
  • single ddlog compiler (JVM) boot up
• Automatic deepdive compile by deepdive do-like commands
• Greenplum driver checking psql client
• DimmWitted NUMA bug fixes
• Bundled Python virtualenv (extern/bundled/python-virtualenv/requirements.txt)
• Other small yet nasty bugs that used to waste lots of time from many users

[alldefector]

LGTM!