try_background not always unused

"try_background:" was removed, but is still necessary under certain conditions.
Achim had removed too much

not everything was always unused ...
osddbuser.h not needed

it refers to volint.h which doesn't exist in the build directory
osddb directory not used any more

remove references to it
Some unused code removed and minor corrections

rxosd is always pthreaded.
HSM-Status is a character

so print it as character: "r" regular file, "p" premaigrated, "m" migrated
Use types as required by libhpss.so

should be as close as possible to hpss software...
No support for NT, probably always large file support
Use flag again

The flag as parameter for many subroutines is interpreted with
bit masks rather than as integer. The name flag is neutral, the
information is visible in the bit names.
newId is needed in case of non NAMEI volservers
Dangerous bug!!

in AllocMetadataEntry the last patch by Achim changed the way
the end of the alloc table entry was calculated to point 40 bytes
after the end of the alloc table entry. This resulted in never
allocating the next alloc table entry writing all further
entries to the same place.

The old calculation is now back here.
Let "new" be again afs_int32

Otherwise "fs fidreplace xxx -1" to remove a copy isn't possible any more.
Allow again "vos convertROtoRW" for osd volumes

With taking openafs's original namei_ops.c in the vol-subdirectory
this feature was broken because the volserver didn't know how to
handle the osdMetadata volume spaecial file. Now after a vos convert
the osdMetadata file is removed when the volume had no osdPolicy
otherwise it is kept and the also in the volume header file
correctly denoted.
Keep OsdMetadata file even if osdPolicy == 0

During "vos convertROtoRW" processing we should not remove the
OsdMatadata file for volumes without osdPolicy because the vnode files
don't contain the vnode magic numbers. Without the Osdmetadata file the
salvager would not load libafsosd and check the vnode magic numbers. This
would result in deleting all files and directories.
Upgrade to OpenAFS level 1.6.6

This new version is now opanfs-1.6.6-osd.
Don't forget to call regen.sh after git pull and before configure
Use nChunksAtOnce instead of NCHUNKSATONCE

Updrading to 1.6.6 I hadn't seen this one.
clear some fields in vldbentry

In ConvertRO two vldb entries are compared by memcmp. The contents of
unused fields is random which had the effect that the entries appeared
to be different (and therefore "vos convertRotoRW" didn't work).
Restore also if DV doesn't match exactly

Allow restore also if DV of archive is slightly higher than DV in vnode.
May happen after salvage (?)
Repair broken SizeDumpVnode

Since ever vn_length_hi vos not taken into account. Also for
OSD-files the size of the metadata was not added. The new version
is now exact within 80 bytes which is much better than before:
A certain volume with 9.255 TB net data was calculated to 1.8 TB!
Two minor bug fixes

at one #if defined the brackets were missing and
NewTrans doesn't return a struct NewTrans*, but a struct volser_trans*!