Move all core plugins over to framework/plugins.

This should have no impact functionality-wise.
The statistics plugin was left out a) as an example and b) because it
was committed by mistake in the first place and was never meant to be a
real plugin.

volatility/framework/plugins/linux/pstree.py

@@ -0,0 +1,51 @@
+from volatility.framework.objects import utility
+from volatility.plugins.linux import pslist
+
+
+class PsTree(pslist.PsList):
+    """Plugin for listing processes in a tree based on their parent process ID """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self._processes = {}
+        self._levels = {}
+        self._children = {}
+
+    def find_level(self, pid):
+        """Finds how deep the pid is in the processes list"""
+        seen = set([])
+        seen.add(pid)
+        level = 0
+        proc = self._processes.get(pid, None)
+        while proc is not None and proc.parent != 0 and proc.parent.pid not in seen:
+            ppid = int(proc.parent.pid)
+
+            child_list = self._children.get(ppid, set([]))
+            child_list.add(proc.pid)
+            self._children[ppid] = child_list
+            proc = self._processes.get(ppid, None)
+            level += 1
+        self._levels[pid] = level
+
+    def _generator(self):
+        """Generates the """
+        for proc in self.list_tasks(self.context, self.config['primary'], self.config['vmlinux']):
+            self._processes[proc.pid] = proc
+
+        # Build the child/level maps
+        for pid in self._processes:
+            self.find_level(pid)
+
+        def yield_processes(pid):
+            proc = self._processes[pid]
+            row = (proc.pid,
+                   proc.parent.pid,
+                   utility.array_to_string(proc.comm))
+
+            yield (self._levels[pid] - 1, row)
+            for child_pid in self._children.get(pid, []):
+                yield from yield_processes(child_pid)
+
+        for pid in self._levels:
+            if self._levels[pid] == 1:
+                yield from yield_processes(pid)