Auto-complete keywords (for, where, filter, ...) and symbol names (names
of protocols, tables, ...). Client can request daemon for list of all
symbols using new cli command `refresh symbols`.
Next changes:
- Behavior is configured by *.Y files using flags CLI_SF_*
- The file doc/reply_codes was moved to header file
client/reply_codes.h.
- Share birdcl input_read() function code for birdc non-interactive
mode.
- BIRD daemon notifies the client about new symbol set.
- BIRD pushes notification to the client about new symbol set and then
the client should request a package with all symbols (`refresh
symbols`).
- File-based history of previous commands(). In interactive mode in
birdc is stored history of all commands in ~/.birdc_history file.
- BIRD daemon sends notification to clients about interface updates
- Maintains a list of all connected cli clients to daemon. Daemon
sends to all cli clients notification about interfaces states up and
down.
