Merge branch '3.1'

common/Makefile.am

common/avl/avl.c

common/avl/avl.h

common/bitfield.c

common/bitfield.h

common/cdc/Makefile.am

common/cdc/adler32.c

common/cdc/adler32.h

common/cdc/cdc.c

common/cdc/md5.c

common/cdc/md5.h

common/cdc/rabin.c

common/cdc/srabin.c

common/cdc/srabin.h

common/diff-simple.h

common/fs-mgr.c

common/fs-mgr.h

common/index/index.c

common/index/index.h

common/info-mgr.c