Fixed: - (CGSize)sizeWithFont:(CPFont)aFont inWidth:(float)aWidth adjust +1 to the computed size

The width computing of a string is always a little random, and that led to truncated labels. This patch adds
a pixel in width in order to fix any rounding errors.

AppKit/Platform/DOM/CPPlatformString.j

@@ -151,7 +151,7 @@ var DOMFixedWidthSpanElement    = nil,
     else if (CPFeatureIsCompatible(CPJavaScriptTextContentFeature))
         span.textContent = aString;
 
-    return CGSizeMake(span.clientWidth, span.clientHeight);
+    return CGSizeMake(span.clientWidth + 1, span.clientHeight);
 }
 
 + (CPDictionary)metricsOfFont:(CPFont)aFont

AppKit/_CPToolTip.j

@@ -118,12 +118,6 @@ var _CPToolTipHeight = 24.0,
         textFrameSizeSingleLine = [aText sizeWithFont:font],
         textFrameSize = [aText sizeWithFont:font inWidth:(aToolTipSize.width)];
 
-    // this small adjustement seems to fix all
-    // tooltips sizing issues. Now I'm not sure why
-    // we need this.
-    textFrameSizeSingleLine.width += 1;
-    textFrameSize.width += 1;
-
     // If the text fully fits within the maximum width, shrink to fit.
     if (textFrameSizeSingleLine.width < aToolTipSize.width)
     {