Config: close #189; added new method getopts()

- Changed all of the scripts in bin to use Config->new then
  $cfg->getopts() in order to parse the script arguments
db_tool: removed extra POD, expanded DESCRIPTION in POD
45-DBTool.t: close #187; added Config object for testing

- Changed most of the `ok()` tests to be `is()` instead, where tests
  are using string equality `eq` in test comparisons