urlselect.lua 0.4: fixed url pattern matching

- fixed pattern matching for URLs that look like this:
  "Read Lua wiki (https://en.wikipedia.org/wiki/Lua_(programming_language))
  for more information".
- added new bar item urlselect_duplicates for list of duplicate indexes
- added simple osx detection on first run to determine the default open
  command
- changed minimum version checking from 0.4.4 to 1.0
- fixed the is_displayed and is_highlighted parameter of hook_print
  callback from string to integer
urlselect.lua 0.4: use hook_process instead of io.popen
colorize_nick.py 16: use weechat config facilities
colorize_nicks.py 16: cleanup and minor simplifications

* remove unused variables
* do some code linting
* simplify some repeated code