devtools/madb: initial version of the 'madb name' command

The 'madb name' command provides several child commands used for human
friendly device nicknames. For now, these device nicknames are not
used by other commands, and the mapping information is just stored
under ~/.madb_names file.

Change-Id: Id5765e3eca5080d0881a2379be355f9c62bc98f4
4 files changed