Log Message:
Update to 1.4.48.  Add patches to fix build on OSX.

Changes since 1.4.46:

  * tcadb.cc (tcadbmisc): compilation warnings ware supressed.
  * tchdb.cc (tchdbfbpmerge): size checking was added.
  * tcbdb.cc (tcbdbrangeimpl): a bug of dead locking was fixed.