pgsql: Put back bufmgr.h in bufpage.h -- it is needed by some macros.

Log Message:
-----------
Put back bufmgr.h in bufpage.h -- it is needed by some macros.

Remove #include bufmgr.h from (most?) source files which already include
bufpage.h.

Modified Files:
--------------
    pgsql/src/backend/access/gin:
        ginentrypage.c (r1.13 -> r1.14)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/gin/ginentrypage.c?r1=1.13&r2=1.14)
    pgsql/src/backend/access/heap:
        heapam.c (r1.256 -> r1.257)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/heapam.c?r1=1.256&r2=1.257)
        hio.c (r1.69 -> r1.70)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/hio.c?r1=1.69&r2=1.70)
        pruneheap.c (r1.10 -> r1.11)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/pruneheap.c?r1=1.10&r2=1.11)
        rewriteheap.c (r1.11 -> r1.12)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/heap/rewriteheap.c?r1=1.11&r2=1.12)
    pgsql/src/backend/access/transam:
        xlog.c (r1.305 -> r1.306)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlog.c?r1=1.305&r2=1.306)
        xlogutils.c (r1.52 -> r1.53)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/access/transam/xlogutils.c?r1=1.52&r2=1.53)
    pgsql/src/backend/commands:
        analyze.c (r1.120 -> r1.121)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/analyze.c?r1=1.120&r2=1.121)
    pgsql/src/backend/storage/buffer:
        bufmgr.c (r1.229 -> r1.230)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/storage/buffer/bufmgr.c?r1=1.229&r2=1.230)
    pgsql/src/include/storage:
        bufpage.h (r1.78 -> r1.79)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/storage/bufpage.h?r1=1.78&r2=1.79)