Fix spelling mistakes

docs/ports.rst

@@ -64,7 +64,7 @@ minimum.
 Connections
 -----------
 Connection between two items is established by creating a constraint
-between handle's postion and port's positions (positions are constraint
+between handle's position and port's positions (positions are constraint
 solver variables).
 
 `ConnectHandleTool` class provides functionality to allow an user to

docs/solver.rst

@@ -1,7 +1,7 @@
 Constraint Solver
 =================
 
-Gaphas' constraint solver can be consider the hart of the Canvas (The Canvas instance holds and orders the items that are drawn on it and in the end will be displayed to the user).
+Gaphas' constraint solver can be consider the heart of the Canvas (The Canvas instance holds and orders the items that are drawn on it and in the end will be displayed to the user).
 
 The constraint solver ('solver' for short) is called during the update of the canvas.
 

docs/tools.rst

@@ -35,7 +35,7 @@ There is a lot of behaviour possible and it can depend on the kind of diagrams t
 
 To organize the event sequences and keep some order in what the user is doing Tools are used. Tools define what has to happen (find a handle nearly the mouse cursor, move an item).
 
-Gaphas contains a set of default tools. Each tool is ment to deal with a special part of the view. A list of responsibilities is also defined here:
+Gaphas contains a set of default tools. Each tool is meant to deal with a special part of the view. A list of responsibilities is also defined here:
 
 :HoverTool:
   First thing a user wants to know is if the mouse cursor is over an item. The ``HoverTool`` makes that explicit.