Remove C++ escaping from *Py.xml templates

Now all escaping required for the C++ code generation is done when the
.cpp/.h files are generated. Previously, only newlines were escaped
automatically. This was a) inconsistent and b) leaked c++ details into
the xml data.
In addition, the escaping is now done in one central place, harmonizing
the three previous implementations.

Pre-existing c++ escape sequences in the XML files have been replaced by
their literal equivalent so that the resulting python doc sting remains
unchanged.

src/Mod/Path/App/AreaPy.xml

@@ -13,8 +13,10 @@
       Delete="true">
     <Documentation>
       <Author Licence="LGPL" Name="Zheng, Lei" EMail="realthunder.dev@gmail.com" />
-      <UserDocu>FreeCAD python wrapper of libarea\n
-Path.Area(key=value ...)\n
+      <UserDocu>FreeCAD python wrapper of libarea
+
+Path.Area(key=value ...)
+
 The constructor accepts the same parameters as setParams(...) to configure the object
 All arguments are optional.</UserDocu>
     </Documentation>
@@ -25,7 +27,8 @@ All arguments are optional.</UserDocu>
     </Methode>
     <Methode Name="setPlane">
       <Documentation>
-          <UserDocu>setPlane(shape): Set the working plane.\n
+          <UserDocu>setPlane(shape): Set the working plane.
+
 The supplied shape does not need to be planar. Area will try to find planar
 sub-shape (face, wire or edge). If more than one planar sub-shape is found, it
 will prefer the top plane parallel to XY0 plane. If no working plane are set,
@@ -35,9 +38,13 @@ same algorithm</UserDocu>
     </Methode>
     <Methode Name="getShape" Keyword='true'>
       <Documentation>
-          <UserDocu>getShape(index=-1,rebuild=False): Return the resulting shape\n
-\n* index (-1): the index of the section. -1 means all sections. No effect on planar shape.\n
-\n* rebuild: clean the internal cache and rebuild</UserDocu>
+          <UserDocu>getShape(index=-1,rebuild=False): Return the resulting shape
+
+
+* index (-1): the index of the section. -1 means all sections. No effect on planar shape.
+
+
+* rebuild: clean the internal cache and rebuild</UserDocu>
       </Documentation>
     </Methode>
     <Methode Name="makeOffset" Keyword='true'>

src/Mod/Path/App/FeatureAreaPy.xml

@@ -20,7 +20,8 @@
         </Methode>
         <Methode Name="setParams" Keyword="true">
             <Documentation>
-                <UserDocu>setParams(key=value...): Convenient function to configure this feature.\n
+                <UserDocu>setParams(key=value...): Convenient function to configure this feature.
+
 Same usage as Path.Area.setParams(). This function stores the parameters in the properties.</UserDocu>
             </Documentation>
         </Methode>

src/Mod/Path/PathSimulator/App/PathSimPy.xml

@@ -13,35 +13,46 @@
       Delete="true">
     <Documentation>
       <Author Licence="LGPL" Name="Shai Seger" EMail="shaise_at_g-mail" />
-      <UserDocu>FreeCAD python wrapper of PathSimulator\n
-PathSimulator.PathSim():\n
-Create a path simulator object\n</UserDocu>
+      <UserDocu>FreeCAD python wrapper of PathSimulator
+
+PathSimulator.PathSim():
+
+Create a path simulator object
+</UserDocu>
     </Documentation>
     <Methode Name="BeginSimulation" Keyword='true'>
       <Documentation>
-          <UserDocu>BeginSimulation(stock, resolution):\n
-Start a simulation process on a box shape stock with given resolution\n</UserDocu>
+          <UserDocu>BeginSimulation(stock, resolution):
+
+Start a simulation process on a box shape stock with given resolution
+</UserDocu>
       </Documentation>
     </Methode>
     <Methode Name="SetToolShape">
       <Documentation>
-          <UserDocu>SetToolShape(shape):\n
-Set the shape of the tool to be used for simulation\n</UserDocu>
+          <UserDocu>SetToolShape(shape):
+
+Set the shape of the tool to be used for simulation
+</UserDocu>
       </Documentation>
     </Methode>
     <Methode Name="GetResultMesh">
       <Documentation>
         <UserDocu>
-          GetResultMesh():\n
-          Return the current mesh result of the simulation.\n
+          GetResultMesh():
+
+          Return the current mesh result of the simulation.
+
         </UserDocu>
       </Documentation>
     </Methode>
     <Methode Name="ApplyCommand" Keyword='true'>
       <Documentation>
         <UserDocu>
-          ApplyCommand(placement, command):\n
-          Apply a single path command on the stock starting from placement.\n
+          ApplyCommand(placement, command):
+
+          Apply a single path command on the stock starting from placement.
+
         </UserDocu>
       </Documentation>
     </Methode>