Thread: pgsql: Rename our substitute qsort to pg_qsort at the link-symbol level

Log Message:
-----------
Rename our substitute qsort to pg_qsort at the link-symbol level (but
provide a macro so code can still just say qsort).  Avoids linker warnings
on pickier platforms such as Darwin, and outright failure on MSVC.

Modified Files:
--------------
    pgsql/src/include:
        port.h (r1.104 -> r1.105)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/port.h.diff?r1=1.104&r2=1.105)
    pgsql/src/port:
        qsort.c (r1.11 -> r1.12)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/qsort.c.diff?r1=1.11&r2=1.12)