[Open Assets] no respawning during multiplayer bosses 2.1

• the script has been updated to take advantage of 2.2.9's new CV_Set function; as a result 2.0 will not work with 2.2.8 or older versions
• a new console variable has been added: allowrespawningduringbosses, this console variable will prevent the script from changing coopstarposts when the map changes if set to yes, effectively disabling the script; it defaults to no
• nonbosscoopstarposts will now set to the same value as coopstarposts when the script is initially loaded if coopstarposts is not set to teamwork
• if the value of nonbosscoopstarposts is changed while in a non-boss map, it will now update coopstarposts immediately instead of waiting for the next non-boss map to change it
• if the value of allowrespawningduringbosses is changed while in a boss map, coopstarposts will be updated immediately to account for the change