Reshuffle czar and css python to simplify layout; rework SConscript to accomodate

Implement snapshot with newer kvinterface.

Having css python under core/modules forced the build system to accommodate
having multiple python modules (with swig) in one system. The build system
also needed support for internal shared libraries so that multiple swigged
c++ code could share code, breaking the previous model where all required
.cc files were linked directly into the swigged python .so.
Fix wait-bug in Executive
Fix getChildren for KvInterfaceImplMem causing failure in testFacade
Remove KvInterfaceImplZoo
Remove AsyncQueryManager, ChunkQuery, and most of dispatcher.cc