Add hasFeatNamed to PlayerCharacter, and use when getFeatNamed was checked against null
(hasFeatNamed as a boolean cannot destroy information, getFeatNamed can, since the PC may have more than one)

Issue#: CODE-1921


git-svn-id: svn+ssh://svn.code.sf.net/p/pcgen/code/Trunk@22782 ef53c05b-3124-4d59-ae7d-fe3273f42be7