merge new pull requests from FlatCAM->master

implement  executing of tasks  inside worker thread
cleanups, reimplement  Isolate/New/OpenGerber as OOP style Shell commands
disable edit  during shell execution,  show   some  progress
add ability for breakpoints in other threads and only if available
add X11 safe flag, not sure what happen on windows

tclCommands/TclCommandNew.py

@@ -0,0 +1,40 @@
+from ObjectCollection import *
+from PyQt4 import QtCore
+import TclCommand
+
+
+class TclCommandNew(TclCommand.TclCommand):
+    """
+    Tcl shell command to starts a new project. Clears objects from memory
+    """
+
+    # array of all command aliases, to be able use  old names for backward compatibility (add_poly, add_polygon)
+    aliases = ['new']
+
+    # dictionary of types from Tcl command, needs to be ordered
+    arg_names = collections.OrderedDict()
+
+    # dictionary of types from Tcl command, needs to be ordered , this  is  for options  like -optionname value
+    option_types = collections.OrderedDict()
+
+    # array of mandatory options for current Tcl command: required = {'name','outname'}
+    required = []
+
+    # structured help for current command, args needs to be ordered
+    help = {
+        'main': "Starts a new project. Clears objects from memory.",
+        'args':  collections.OrderedDict(),
+        'examples': []
+    }
+
+    def execute(self, args, unnamed_args):
+        """
+        execute current TCL shell command
+
+        :param args: array of known named arguments and options
+        :param unnamed_args: array of other values which were passed into command
+            without -somename and  we do not have them in known arg_names
+        :return: None or exception
+        """
+
+        self.app.on_file_new()