Fix incorrect default for xaxes/yaxes tickColor.

The way in which xaxes/yaxes inherit options from xaxis/yaxis resulted
in a minor bug, where tickColor defaulted to the xaxis/yaxis color
instead of the color for its axis.  Fixed by applying the default before
extending the per-axis options, resolving #984.

There's still some questionable behavior here; this section should be
revisited for 0.9, especially with an eye towards removing some of the
code that only exists for backwards-compatibility.

jquery.flot.js

@@ -674,8 +674,15 @@ Licensed under the MIT license.
 
             axisCount = options.xaxes.length || 1;
             for (i = 0; i < axisCount; ++i) {
-                axisOptions = $.extend(true, {}, options.xaxis, options.xaxes[i]);
+
+                axisOptions = options.xaxes[i];
+                if (axisOptions && !axisOptions.tickColor) {
+                    axisOptions.tickColor = axisOptions.color;
+                }
+
+                axisOptions = $.extend(true, {}, options.xaxis, axisOptions);
                 options.xaxes[i] = axisOptions;
+
                 if (axisOptions.font) {
                     axisOptions.font = $.extend({}, fontDefaults, axisOptions.font);
                     if (!axisOptions.font.color) {
@@ -686,8 +693,15 @@ Licensed under the MIT license.
 
             axisCount = options.yaxes.length || 1;
             for (i = 0; i < axisCount; ++i) {
-                axisOptions = $.extend(true, {}, options.yaxis, options.yaxes[i]);
+
+                axisOptions = options.yaxes[i];
+                if (axisOptions && !axisOptions.tickColor) {
+                    axisOptions.tickColor = axisOptions.color;
+                }
+
+                axisOptions = $.extend(true, {}, options.yaxis, axisOptions);
                 options.yaxes[i] = axisOptions;
+
                 if (axisOptions.font) {
                     axisOptions.font = $.extend({}, fontDefaults, axisOptions.font);
                     if (!axisOptions.font.color) {