qmpfw: Quick Mesh Project legacy firmware generator (deprecated)

Adds a new way to generate/store the configuration files for each target:
There are profiles (such as ath-qmp-small-node) which are shared between all similar kind of devices (i.e ubiquiti devices)
And individual configurations (optional) which can be used to specify extra options for the device

Adds support for new special target "ar71xx" which compiles the firmware for all atheros AR7/9 devices.