task/ta-npp-002-07 -- filterdaemon.py get_files facility

nparcel/b2cconfig.py
* new attribute t1250_file_format

nparcel/conf/nparceld.conf
* placeholder for the new t1250_file_format config option

nparcel/filterdaemon.py
* expanded the get_files() method to checks inbound directories
  for valid T1250 files to process

nparcel/mapperdaemon.py
* refactored the get_files() method to use the nparcel/utils/files.py
  variant of check_filename

nparcel/utils/files.py
* refactored the check_filename() function to match with regexs