(Steve Murphy) Added the ability to run an external script whenever an IP is blocked. Two new config variables were added to support this feature, ENABLE_EXT_BLOCK_SCRIPT_EXEC and ENABLE_EXT_BLOCK_SCRIPT_EXEC.
Bug fix to not create zombie whois processes when whois lookups take too long to complete for whatever reason (slow network, etc.). This fixes issue #15 on Github. The bug was reported by "3Turtles" to the psad mailing list, and Dan Dickey provided valuable input.