kes Implement new prunning code that prunes up to 1000 jobs at

kes  Implement new prunning code that prunes up to 1000 jobs at
     the same time.  The same technique can be applied to a number
     of other prune/purge subroutines.
kes  Add an insanity check when starting a new tape job to ensure
     that the tape position has not been changed. If so fail the
     job.
kes  Fix Win32 build for dlls to add the folllowing:
     src/lib/bsock.c -- new file with new entry points
     src/lib/dlist.c  -- new entry points
     src/cats/sql_create.c -- new entry point
     src/cats/sql_cmds.c -- new DATA item exported

git-svn-id: https://bacula.svn.sourceforge.net/svnroot/bacula/trunk@4383 91ce42f0-d328-0410-95d8-f526ca767f89