DM-1661: czar log4cxx link/load bug on Ubuntu 14.04

On Ubuntu 14.04, the czar would fall over at load time with an unresolved
sym (for typeinfo for log4cxx::helpers::ObjectPtrBase) while loading the
css python wrapper shared lib. It seems the linker was tripping up chasing
transitive dependencies through the shared libs.

This cl tweaks core/modules/Sconscript to provide additional explicit link libs
to "shmod" shared modules to hint the linker.
Merge branch 'u/fritzm/DM-1661'
Implement unit test for CSS version string handling (DM-1621).

There are two unit test actually, one on C++ side implemented as few
additional checks in css/testFacade, and one on python side in
admin/tests/test_cssVersion.py. Tests needed few additional changes to
other classes:
- QservAdmin constructor now takes either connInfo or config argument,
  this is passed directly to KvInterface.newImpl. This makes it possible
  to test QservAdmin against in-memory data, no Zookeeper needed.
- C++ class css/Facade has new static method which returns version
  number. This is useful for tests only, other clients should not need
  to care about versions.
- testKvInterfaceImpl and testFacade were added to the list of unit
  tests that we run at build time.
- Python class KvInterfaceMem (in css/python/kvInterface.py) has few
  fixes to  make it compatible with KvInterfaceZoo and
  KvInterfaceImplMem.
Minor cleanup for variable names defining version number.

Also use booss::lexical cast to convert integer version number into
its string representation instead of defining them separately.
Merge branch 'u/salnikov/DM-1621'
updated release notes for 2014_12 (1st cut)
Fixing overlap parameter issue (DM-1678)

Add required configuration option part.default-overlap which will be
stored as per-database overlap value in CSS. Per-table value is still
stored as before (from part.overlap config parameter).
Merge branch 'u/salnikov/DM-1678'
First version of multi-worker data loader.

This makes an initial implementation of the data loader with support for
multiple worker nodes (DM-1653). data-loader.py gets new option -W which
can be used multiple times to specify one or more worker host name.
Currently there is no way to specify different mysql port number for
different workers, all worker database servers are supposed to listen on
the same port. Mapping of chunks to hosts is currently done in a
round-robin mode, and of course different tables use the same chunk
mapping (see admin/chunkMapping module).