SoftSnow XChat Filter 1.2.3 (from backup file)

SoftSnow XChat Filter 1.2.3 (from backup file)

Expand list of commands to include DEBUG, PRINT, ALLOW, ADD, DELETE,
SAVE and LOAD.
 * DEBUG prints information about chanel, server, network and host
   from IRC::get_info(<n>)
 * PRINT writes out all rules used, both 'allow' and 'deny'
 * ALLOW to switch between using and not using 'allow'  rules,
   taken into account before 'deny' rules.  This allow for example
   showing '@search' lines, even if this rule matches one of 'deny'
   rules.  Currently list of rules is hardcoded in @allow_rules
 * ADD allows to add (append) rule to filter
 * DELETE allows to delete last rule, or rule with given number
 * SAVE and LOAD (or RELOAD) to save or load list of rules, one rule
   per line, to '~/.xchat/SoftSnow_filter.conf' file ($filter_file)

Move all filters from body of isFiltered() subroutine to @filter_deny
as string literals, using '(?i)' extended regexp syntax as prefix to
mark case-insensitive regexps (using string literals allow easy saving
and restoring filter).

Use IRC::get_info(7) instead of IRC::get_info(3) to be more exact when
filter is limited to single server: better support for limited
filtering together witha utoreconnect feature.

Signed-off-by: Jakub Narebski <jnareb@gmail.com>