This CL moves the network address parsing function from adb to libbase
so that it can be used by fastboot as well as adb.
libbase seemed like the right choice because:
1. It already has some parsing functions (parseint)
2. The net address parsing function uses the libbase string
functions so we have a libbase dependency anyway.
The parsing function has been modified slightly to make the canonical
address optional, and debug logging on success has been removed.
For adb the only functional difference is that parsing a network
address will no longer print the result to the debug log, which seemed
unnecessary.
Bug: http://b/26236380
Change-Id: Ife6df02937225fc66de87884d3572d79c092c522
