DRTVWR-418: Fix C++ errors detected by Xcode 9.

You can't legitimately perform an ordered comparison between a pointer and an
int, even 0. Fix a number of 'if (ptr > 0)' to plain 'if (ptr)'.

Fix LLEditWearableDictionary::WearableEntry constructor to avoid varargs
mechanism. It used to accept three different counts, followed by three
different lists of enums, fetched in each case as 'int' -- dubious in itself.
The constructor body performed three different loops to populate those enums
into three different member vectors.

Instead, make the constructor accept three vectors and initialize the member
vectors from the passed vectors. Now that C++ has inline vector
initialization, change existing constructor calls to pass temporary vectors
initialized with what used to be the varargs enum values.