Add BaseTypes docs.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@1268 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

doc/Size.txt

@@ -0,0 +1,11 @@
+OpenLayers.Size
+
+This class represents a width/height pair.
+
+* Constructor
+  OpenLayers.Size({float|h}, {float|w}) -- Create Size.
+
+* Methods
+  toString() -- {String} -- Converts to human readable string.
+  clone() -- {OpenLayers.Size} -- Returns a copy of the pixel.
+  add({int|x}, {int|y}) -- {OpenLayers.Size} -- add x and y to the current coordinates.