DEVEL15-windows-cm-buf-misc-20080229

DEVEL15-windows-cm-buf-misc-20080229

LICENSE MIT

(1) Add an undocumented store behind mode for use in testing.  Set
    EnableSMBAsyncStore to 2.  When set all smb_WriteData calls are
    background writes, all calls to cm_FSync are skipped and file close
    operations do not block for dirty buffers to be written.  This
    permits all writes to be performed in the buf_IncrSyncer thread.

(2) Do not use I64 in osi_Log() format strings as all parameters are
    converted to size_t which is 32-bit on 32-bit Windows.

(3) Reduce the number of times the cm_buf_t mutex is obtained, dropped,
    obtained, dropped in buf_IncrSyncer

(4) In buf_CleanAsyncLocked, request that a full chunk be written instead
    of just the current buffer.  cm_SetupStoreBIOD will stop at the
    first clean buffer.  This reduces the overall number of RPCs that
    must be performed.

(5) Define CM_BUF_VERSION_BAD and use it instead of -1.

(cherry picked from commit 114de458ca7717cf0bcda90df61f24495fe8f922)