1.4 non-portable: changed 'reload' behaviour and '-f refresh'

This solves #212 (closed) and #221 (closed) in a minimal way possible, but I also think it's a better way than adding new commands. See the commit messages for more info.

In a nutshell:

• knotc reload doesn't trigger instarefresh/notify for existing zones - if the zone doesn't change, the timers are left as they are (there's a 'expire' command for this special case anyway)
• knotc refresh respects the -f (force) flag, if the refresh is forced zones are retransferred without comparing master/slave SOA serial first

Note: changes are not portable to master, they should be solved properly with zone events (reload), and with the new config/remote protocol later on (retransfer).