tool: add command line tool for managing system-info

tool: add command line tool for managing system-info

USAGE
  system-into-tool [OPTION]

OPTION
  -l|--list-all                  List all system-info database entries
  -g|--get KEY [-v|--verbose]    Get value of feature KEY
                                 If -v option is given, shows result in detail
                                 ex) system-info-tool -g tizen.org/feature/display
                                     system-info-tool -g tizen.org/system/manufacturer -v
  -s|--set KEY TYPE VALUE        Add or update user-defined KEY
                                 Available TYPE: bool, int, double, string
                                 ex) system-info-tool -a tizen.org/feature/display bool 1
                                     system-info-tool -a tizen.org/system/manufacturer string Tizen
  -c|--clear KEY                 Clear user-defined KEY. This cannot clear read-only system key
  -C|--clear-all                 Clear all user-defined keys
  -h|--help                      Show this help

Change-Id: Id2f72ee242e12d90edc82797a21fdb8b097e2bc6
Signed-off-by: Youngjae Cho <y0.cho@samsung.com>