DATA-978
- pfcr_feats.lst: Tweak to Arcane Strike implementation to allow cleaner extending
- pfapg_feats_mods.lst: Added Arcane Strike extension to Summoner/Witch
- pfum_feats.lst: Added Arcane Strike extension to Magus

git-svn-id: svn+ssh://svn.code.sf.net/p/pcgen/code/Trunk@20567 ef53c05b-3124-4d59-ae7d-fe3273f42be7