add python setuptools support

- add setup.py script,
 - switch to use images via "share:" resource name
   (this allows to work both versions of application:
     - system wide installation,
     - directly from source),
 - add .desktop file,
 - rename FlatCAM.py to flatcam and install it as an
   executable script.

flatcam

@@ -0,0 +1,35 @@
+#!/usr/bin/env python2
+############################################################
+# FlatCAM: 2D Post-processing for Manufacturing            #
+# http://flatcam.org                                       #
+# Author: Juan Pablo Caram (c)                             #
+# Date: 2/5/2014                                           #
+# MIT Licence                                              #
+############################################################
+
+import sys
+from PyQt4 import QtGui
+from PyQt4 import QtCore
+from FlatCAMApp import App
+
+
+def debug_trace():
+    """
+    Set a tracepoint in the Python debugger that works with Qt
+    :return: None
+    """
+    from PyQt4.QtCore import pyqtRemoveInputHook
+    #from pdb import set_trace
+    pyqtRemoveInputHook()
+    #set_trace()
+
+debug_trace()
+
+# All X11 calling should be thread safe otherwise we have strange issues
+# QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_X11InitThreads)
+# NOTE: Never talk to the GUI from threads! This is why I commented the above.
+
+app = QtGui.QApplication(sys.argv)
+QtCore.QDir.setSearchPaths("share", QtCore.QStringList(("share", "share/flatcam", "/usr/share/flatcam")));
+fc = App()
+sys.exit(app.exec_())