module for parsing command line arguments

 Getopt::Declare provides facilities to parse command line options. It builds
 and runs a parser. The parser object can be saved and later run on different
 input. Key features are:
 .
  * Automatic generation of error, usage and version information
  * Matching of parameter components may be constrained by regular expressions
  * Execution of embedded actions
  * Declarative specification of inter-parameter relationships
  * Selective or global case-insensitive matching of parameters