Agent for accessing '/var/yp/Makefile'
======================================

The agent is designed to read/write this Makefile. It reads/writes
variables and "all:" rule. Currently it is not possible to add a new
entries to the Makefile, just change the existing ones.

Implemented paths:

Read (.var.yp.makefile) -> <map>

- returns map with all variables

Read (.var.yp.makefile.maps) -> <list>

- returns list of maps in the "all:" rule

Read (.var.yp.makefile.<VARIBLE>) -> (string>

- returns value of VARIABLE (empty string if does
  not exists)

Write (.var.yp.makefile, <map>) -> <boolean>

- saves values of the variables in the map

Write (.var.yp.makefile.maps, <list>) -> <boolean>

- save the rule "all:"

Write (.var.yp.makefile.<VARIABLE>, <string>) -> <boolean>

- save the VARIABLE

Write (.var.yp.makefile, nil)

- writes (physically) the file by copying the original one and
  replacing the overwritten values


Note: all writes returns true on success false on error.