Add categories and favicon

* Reorganize resource directories (templates, less, static)
* Show categories on index
* Add favicon

res/less/song.less

@@ -0,0 +1,78 @@
+@import "colors.less";
+
+table.chordedline {
+    border-spacing: 0px;
+    display: inline-block;
+}
+
+.song div {
+    padding: 0.5em 0;
+}
+
+.chordedline td {
+    padding: 0px;
+}
+
+.chord {
+    font-style: italic;
+    color: @chord-color;
+}
+
+div.chorus {
+    font-weight: bold;
+    border-left: black 2px solid;
+    padding-left: 0.5em;
+    div {
+        padding-left: 0.5em;
+    }
+    table {
+        margin-left: 0;
+        padding-left: 0;
+        padding-right: 0;
+    }
+}
+
+.rrep {
+    background-image: url(repeat-sign.svg);
+    display: inline-block;
+    width: 1em;
+    height: 2em;
+}
+
+.lrep {
+    -moz-transform: scaleX(-1);
+    -o-transform: scaleX(-1);
+    -webkit-transform: scaleX(-1);
+    transform: scaleX(-1);
+    filter: FlipV;
+    -ms-filter: "FlipV";
+    .rrep();
+}
+
+.rep {
+    font-style: italic;
+}
+
+.echo {
+    font-style: italic;
+}
+
+button, select#transposeSelect {
+    min-width: 2em;
+    min-height: 2em;
+    padding: .4em;
+    border-style: none;
+    border-radius: @border-radius;
+    background-color: @secondary;
+    &:hover {
+        background-color: @secondary-hover;
+        transition-duration: @transition;
+    }
+}
+
+select#transposeSelect {
+    -webkit-appearance: none;
+    -moz-appearance: none;
+    font-weight: bold;
+    color: black;
+}