Resolve "Raise warning level and fix warnings on MSVC"

This MR resolves all warnings at level 3 and quite a few of the warnings at level 4 of MSVC.

The variable renames are mostly because the old names shadows a (member) variable. (possibly of a base class; like the member p of QList). This isn't resolved throughout the whole code base, since this shadowing warning is part of W4.

Closes #188 (closed)

include/colorPlot.h

@@ -101,9 +101,9 @@ public:
     {
         return mMapHeight;
     }
-    inline void setMapHeight(double h)
+    inline void setMapHeight(double height)
     {
-        mMapHeight = h;
+        mMapHeight = height;
     }
     inline void setInvHue(bool b)
     {