dnsmasq component of fruit-config

[herry13]

dnsmasq should be configured by fruit-config to enable DHCP server for a local cluster.

An example of dnsmasq configs:

{
  "dnsmasq": {
    "interface": "eth0",
    "dhcp-range": "10.5.0.10,10.5.0.100,24"
  }
}

• interface - the network interface where dnsmasq should serve. Note that this interface should be configured with a static IP address (see field /network of file fruit.json)
• dhcp-range - consists of 3 values separated by comma: <min-ip>,<max-ip>,<lease-period>. Note that an error will occur when the min-ip and max-ip have different network addresses. An error also occurs when these IPs have different network address comparing to the static address of the interface where dnsmasq will listen to (see field /dnsmasq/interface)

[herry13]

Commit 9d5d959 implemented dnsmasq component that accepts /dnsmasq/interface parameter, but not /dnsmasq/dhcp-range.