Move to less, improved style, fixed bugs

* Redirection wasn't being encoded properly
* CSS to LESS transition
* Improved Makefile
* Explained red color in index
* Unified link and button styles

res/song.css

@@ -1,65 +0,0 @@
-table.chordedline {
-    border-spacing: 0px;
-    display: inline;
-}
-
-.song div {
-    padding: 0.5em 0;
-}
-
-.chordedline td {
-    padding: 0px;
-}
-
-.chord {
-    font-style: italic;
-    color: darkgreen;
-}
-
-.chorus {
-    font-weight: bold;
-    border-left: black 2px solid;
-    padding-left: 0.5em !important;
-}
-
-.chorus div {
-    padding-left: 0.5em;
-}
-
-.chorus table {
-    margin-left: 0;
-    padding-left: 0;
-    padding-right: 0;
-}
-
-.lrep {
-    -moz-transform: scaleX(-1);
-    -o-transform: scaleX(-1);
-    -webkit-transform: scaleX(-1);
-    transform: scaleX(-1);
-    filter: FlipV;
-    -ms-filter: "FlipV";
-    background-image: url(repeat-sign.svg);
-    display: inline-block;
-    width: 1em;
-    height: 2em;
-}
-
-.rrep {
-    background-image: url(repeat-sign.svg);
-    display: inline-block;
-    width: 1em;
-    height: 2em;
-}
-
-.rep {
-    font-style: italic;
-}
-
-button.small {
-    padding: 0.1em;
-}
-
-.echo {
-    font-style: italic;
-}