Charlie Jacobsen authored Feb 13, 2016 and Vikram Narayanan committed Oct 26, 2016

Memory itree code initializes resource tree needed for
address -> cptr translation. Provides interface for other liblcd
code to add/remove from tree (page allocator will use that).

Removed redundant nr_pages_order field from resource tree node. Its
size can be computed from the interval tree node.

Filled in some simple functions that are part of the liblcd
interface. Some are no-ops for isolated code.