mpkg: add the configure function.
mpkg: add the configure function.

This function allows to re-run the postinst script to re-configure any
packages installed but left unconfigured.

Without arguments (ie. package list), mpkg re-configures all unconfigured
packages. Otherwise, it re-configures all packages given into parameters.

Usage: ...
       mpkg [OPTIONS] configure [PACKAGE...]
...

Signed-off-by: Gaël PORTAY <1666f60cfa201a60b0ea694168a0b6932673170a@gmail.com>

gazoo74/mpkg,gazoo74/mpkg