reuse a key if it is found in the dictionary on a set. avoids a reallocation
reuse a key if it is found in the dictionary on a set. avoids
a reallocation



git-svn-id: c4835f16671dea8638df082a44d6e32ac56ef27f@28 d2a1560e-cd8f-e3f8-4df6-3dd88a9042ca

ckhardin/libplist-posix,ckhardin/libplist-posix