Fixed husk cannon shots not registering on the headshot counter.

Made an internal change to support the compound bow which inadvertently deactivated headshot processing on husk cannon. This change reactivates headshots counting on the counter when firing shots; bash was never affected.

Add support for Compound Bow and HRG Incendiary Rifle.

You can spawn them using a modified version of the `giveweapon` lines:

giveweapon headshotcountergamecontent.kfweap_bow_compoundbow_headshotcounter
giveweapon headshotcountergamecontent.kfweap_assaultrifle_hrgincendiaryrifle_headshotcounter

These are the same as the base game's version except for

1. the first part ("headshotcountergamecontent")
2. and the suffix ("_headshotcounter")

the base game looks like:

giveweapon kfgamecontent.kfweap_bow_compoundbow

In general, all my modified weapons use the same weapon names as the base game except for

1. the first part and
2. the extra suffix.

Added Support for weekly and endless game modes.