sysutils/nsysctl 2.2

Utility to get and set the kernel state at runtime, features:

* get or set the system state at runtime, * handle an object up to CTL_MAXNAME levels, * print the right object also with an empty level name, * options to show the properties of a parameter, * output explicitly indicated by the options, * options not mutually exclusive, * output via libxo in human and machine readable formats, * isolated code to manage opaque values, * some string value is parsed to show structured output, * avoid non-primitive data types hardcode via libnv, * debug without recompiling the kernel with SYSCTL_DEBUG.