Initial implementation of the new data loading script.

New loading procedure is implemented as a small bunch of python modules:
  configParser.py - parses "new-style" partitioner configuration files
  partConfig.py   - extracts relevant parameters from partitioner config
  dataLoader.py   - the whole procedure for partitioning data, loading
                    it into database and updating CSS

In addition to the modules that can be imported and used independently
there is a new script data-loader.py which accepts a bunch of command
line options and arguments and calls dataLoder.py to do actual data
loading.

See also DM-621 for discussion.
small improvements in logging
Create empy chunks file, option to skip CSS.

Few improvements following code review:
- new option -E takes file name for empty chunk list, if specified and
  table is partitioned then empty chunk list will be stored in that file
- new option -C disable all CSS operations
- new feature - if both -s and -1 are specified then data is loaded into
  one table without partitioning even for partitioned tables
- improved logging, more INFO messages, all SQL queries are dumped with
  DEBUG level
Create index table, add option to remove existing tables.

- For partitioned tables we now create index on czar side and populate
  it from all loaded chunks. By default database name for index is
  qservMeta, can be changed with -i option, use empty string to disable
  index generation.
- New option -e which enable removal of existing tables from database,
  this works both for data (including all chunk tables) and metadata
  (index).
Use original index column type for the column in index table
Merge branch 'u/salnikov/DM-621'
Fixing the bug introduced by my merge of DM-621

Apparently the change to qservAdmin had qserv failing due to missing
'overlap' parameter at database level. I can't understand how it did
not manifest itself in my testing,. Restoring 'overlap' in database
configuration, this fixes all integration tests.
Work in progress to make qserv build on OS X