Autoreload Nagview (#942)

* Modified autoreload to use new dirwatch infrastructure, and added in nagview to verify that fs changes don't stomp on our changes, unless you want them to.

* Split out reload functionality to actual document, and added in a thread to check the document, in the cases where it wouldn't be covered by dirwatch.

* As per request from jgmdev, added in ability to show nagview always.

* Changed things over to use dirwatch.

* Made sure we redrew things, added in a contingency in 'save' for times when we load a non-existent file, and added some checks.

data/core/doc/init.lua

@@ -80,6 +80,16 @@ function Doc:load(filename)
 end
 
 
+function Doc:reload()
+  if self.filename then
+    local sel = { self:get_selection() }
+    self:load(self.filename)
+    self:clean()
+    self:set_selection(table.unpack(sel))
+  end
+end
+
+
 function Doc:save(filename, abs_filename)
   if not filename then
     assert(self.filename, "no filename set to default to")