irc.rb: add join, unparse methods
irc.rb: namespacify
irc.rb: check for empty args
irc.rb: convert args to strings
irc.rb: use a regexp test for /^:/
irc.rb: use regexp everywhere in place of start_with
irc.rb: disallow trailing as first parameter

Otherwise it would be misparsed as the prefix. (Tags are the zeroth
parameter as they're always followed by the prefix.)
irc.rb: do not crash on empty args list
irc.py: rewrite join() to use the same logic as irc.rb
irc.py: small split() rewrite
irc.rb, irc.py: add tests for join()
irc.rb, irc.py: add tests for split()
irc: exit 1 if any tests failed
irc: split the whitespace tests
irc: accept leading whitespace

Screw what the RFC says, this is simpler.
irc.rb: preserve trailing whitespace