Minor site optimizations (#61)

- Update the Open Chess Set image to the optimized version from the MaterialX repository.
- Consolidate the original, overlapping style sheets into one.
- Modernize the copyright notification in the consolidated style sheet.

Author: jstone-lucasfilm

Contributing.html

@@ -5,10 +5,7 @@
   <title>MaterialX - Contributing</title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;

DeveloperReference.html

@@ -5,10 +5,7 @@
   <title>MaterialX - <a href="DeveloperReference.html">Developer Reference</a></title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;

Specification.html

@@ -5,10 +5,7 @@
   <title>MaterialX - Specification</title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;

ThirdPartySupport.html

@@ -5,10 +5,7 @@
   <title>MaterialX - Third Party Support</title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;

Tools.html

@@ -5,10 +5,7 @@
   <title>MaterialX - ShaderGen and MaterialXView</title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;

images/OpenChessSet_Arnold_01.png

@@ -5,10 +5,7 @@
   <title>MaterialX - Home</title>
 
   <link rel="icon" href="faviconMX.ico" type="image/x-icon" />
-  <link rel="stylesheet" href="style/rst.css" type="text/css">
   <link rel="stylesheet" href="style/default.css" type="text/css">
-  <link rel="stylesheet" href="style/flavor.css" type="text/css">
-  <link rel="stylesheet" href="style/renderman-university.css" type="text/css">
   <style>
     #mainContentContainer {
       left: 15px;