# Functions
NewApp - create new app.
NewAppCommandBase - create new base app command.
NewAppRootCommandBase - create new base root command.
NewAppSubCommandBase - create new base app command.
ReplaceProgName - replace the program name ("$PROG_NAME") in a string.
SetExamplesAtEndOfUsage - set the examples at the end of the usage text.
SetUsageReturnCode - the RC to return when usage is displayed.
SetVersionWithAuthor - show author info in the version.
# Structs
App - application wrapper for root command.
AppCommandBase - base app command.
AppRootCommandBase - base root command.
AppSubCommandBase - base app command.
# Interfaces
AppCommand - the application command interface.
AppRootCommand - root App command interface.
AppSubCommand - sub command interface.