Make the legend using HTML rather than painting on the canvas

This lets us make pieces of it clickable much easier, and gives us lots
more layout tools.  This is in preparation for showing/hiding lines.

Change-Id: I19f17297bf1a47879729e5df4bfaf25aa949d16c
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/frc971/analysis/BUILD b/frc971/analysis/BUILD
index 2d71410..abb950b 100644
--- a/frc971/analysis/BUILD
+++ b/frc971/analysis/BUILD
@@ -70,11 +70,21 @@
     ],
 )
 
+genrule(
+    name = "copy_css",
+    srcs = [
+        "//aos/network/www:styles.css",
+    ],
+    outs = ["styles.css"],
+    cmd = "cp $< $@",
+)
+
 filegroup(
     name = "plotter_files",
     srcs = [
         "index.html",
         "plot_index_bundle.min.js",
+        "styles.css",
     ],
 )
 
diff --git a/frc971/analysis/cpp_plot/BUILD b/frc971/analysis/cpp_plot/BUILD
index 156594c..d6e74c3 100644
--- a/frc971/analysis/cpp_plot/BUILD
+++ b/frc971/analysis/cpp_plot/BUILD
@@ -23,10 +23,21 @@
     ],
 )
 
+genrule(
+    name = "copy_css",
+    srcs = [
+        "//aos/network/www:styles.css",
+    ],
+    outs = ["styles.css"],
+    cmd = "cp $< $@",
+)
+
 filegroup(
     name = "cpp_plot_files",
     srcs = [
+        "cpp_plot_bundle.js",
         "cpp_plot_bundle.min.js",
         "index.html",
+        "styles.css",
     ],
 )
diff --git a/frc971/analysis/cpp_plot/index.html b/frc971/analysis/cpp_plot/index.html
index 776c103..fbb5199 100644
--- a/frc971/analysis/cpp_plot/index.html
+++ b/frc971/analysis/cpp_plot/index.html
@@ -1,6 +1,7 @@
 <html>
   <head>
     <script src="cpp_plot_bundle.min.js" defer></script>
+    <link rel="stylesheet" href="styles.css">
   </head>
   <body>
   </body>
diff --git a/frc971/analysis/index.html b/frc971/analysis/index.html
index edd2483..22b42c7 100644
--- a/frc971/analysis/index.html
+++ b/frc971/analysis/index.html
@@ -1,6 +1,7 @@
 <html>
   <head>
     <script src="plot_index_bundle.min.js" defer></script>
+    <link rel="stylesheet" href="styles.css">
   </head>
   <body>
   </body>