Bug #1022

- Fixed bug #1022, where dependencies were note released when a blocking task
  was completed (thanks to Arkady Grudzinsky).
- The Task object now caches ::is_blocked and ::is_blocking Booleans that are
  determined on pending.data load.
- Simplified and sped up color rule processing using cached values, reducing
  the number of map lookups, and removed loop invariants when the rules are
  not defined.
- Simplified urgency calculations given the cached values for blocked/blocking.
- On load, pending.data is scanned for accurate blocked/blocking status
  determination.
- Obsoleted and removed complex single-task dependency calculations.
- Sped up 'nag' processing by using cached values..
- Modified the 'show' command to consider color.blocking to be valid.
- Added default config value for color.blocking, and included it in the
  precedence list ahead of blocked, as it is more important.
- Updated taskrc.5 man page to include the new color.blocking rule, and its
  place in the rule precedence.

src/dependency.cpp

@@ -39,28 +39,6 @@
 
 extern Context context;
 
-////////////////////////////////////////////////////////////////////////////////
-// A task is blocked if it depends on tasks that are pending or waiting.
-//
-//   1 --> 2(pending)    = blocked
-//   3 --> 4(completed)  = not blocked any more
-bool dependencyIsBlocked (const Task& task)
-{
-  std::string depends = task.get ("depends");
-  if (depends != "")
-  {
-    const std::vector <Task>& all = context.tdb2.pending.get_tasks ();
-    std::vector <Task>::const_iterator it;
-    for (it = all.begin (); it != all.end (); ++it)
-      if ((it->getStatus () == Task::pending  ||
-           it->getStatus () == Task::waiting) &&
-          depends.find (it->get ("uuid")) != std::string::npos)
-        return true;
-  }
-
-  return false;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 void dependencyGetBlocked (const Task& task, std::vector <Task>& blocked)
 {
@@ -76,26 +54,6 @@ void dependencyGetBlocked (const Task& task, std::vector <Task>& blocked)
       blocked.push_back (*it);
 }
 
-
-////////////////////////////////////////////////////////////////////////////////
-// To be a blocking task, there must be at least one other task that depends on
-// this task, that is either pending or waiting.
-bool dependencyIsBlocking (const Task& task)
-{
-  std::string uuid = task.get ("uuid");
-
-  const std::vector <Task>& all = context.tdb2.pending.get_tasks ();
-  std::vector <Task>::const_iterator it;
-  for (it = all.begin (); it != all.end (); ++it)
-    if ((it->getStatus () == Task::pending  ||
-         it->getStatus () == Task::waiting) &&
-        it->has ("depends")                 &&
-        it->get ("depends").find (uuid) != std::string::npos)
-      return true;
-
-  return false;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 void dependencyGetBlocking (const Task& task, std::vector <Task>& blocking)
 {