Integrated the jobprogress library into hscommon

I have a fix to make in it and it's really silly to pretend that this
lib is of any use to anybody outside HS apps. Bringing it back here will
make things more simple.

hscommon/jobprogress/performer.py

@@ -0,0 +1,72 @@
+# Created By: Virgil Dupras
+# Created On: 2010-11-19
+# Copyright 2011 Hardcoded Software (http://www.hardcoded.net)
+# 
+# This software is licensed under the "BSD" License as described in the "LICENSE" file, 
+# which should be included with this package. The terms are also available at 
+# http://www.hardcoded.net/licenses/bsd_license
+
+from threading import Thread
+import sys
+
+from .job import Job, JobInProgressError, JobCancelled
+
+class ThreadedJobPerformer:
+    """Run threaded jobs and track progress.
+    
+    To run a threaded job, first create a job with _create_job(), then call _run_threaded(), with 
+    your work function as a parameter.
+        
+    Example:
+        
+    j = self._create_job()
+    self._run_threaded(self.some_work_func, (arg1, arg2, j))
+    """
+    _job_running = False
+    last_error = None
+    
+    #--- Protected
+    def create_job(self):
+        if self._job_running:
+            raise JobInProgressError()
+        self.last_progress = -1
+        self.last_desc = ''
+        self.job_cancelled = False
+        return Job(1, self._update_progress)
+    
+    def _async_run(self, *args):
+        target = args[0]
+        args = tuple(args[1:])
+        self._job_running = True
+        self.last_error = None
+        try:
+            target(*args)
+        except JobCancelled:
+            pass
+        except Exception as e:
+            self.last_error = e
+            self.last_traceback = sys.exc_info()[2]
+        finally:
+            self._job_running = False
+            self.last_progress = None
+    
+    def reraise_if_error(self):
+        """Reraises the error that happened in the thread if any.
+        
+        Call this after the caller of run_threaded detected that self._job_running returned to False
+        """
+        if self.last_error is not None:
+            raise self.last_error.with_traceback(self.last_traceback)
+    
+    def _update_progress(self, newprogress, newdesc=''):
+        self.last_progress = newprogress
+        if newdesc:
+            self.last_desc = newdesc
+        return not self.job_cancelled
+    
+    def run_threaded(self, target, args=()):
+        if self._job_running:
+            raise JobInProgressError()
+        args = (target, ) + args
+        Thread(target=self._async_run, args=args).start()
+