[IMP] all: new design to match the one on odoo.com

* upgrade to bootstrap 3.3.6

* new Header, port website LESS
  - Add the new header
  - Modify sub-header in order to handle “back” button and version
    switcher
  - Port website’s Less:
    * Use same variables’ names
    * Review fonts and colours in order to fit the new style

* add new footer

* Review and optimise JS code in order properly handle the new header,
  footer and card.top animations

* replace  banner images

_extensions/odoo/static/bootstrap-3.3.6/less/media.less

@@ -0,0 +1,66 @@
+.media {
+  // Proper spacing between instances of .media
+  margin-top: 15px;
+
+  &:first-child {
+    margin-top: 0;
+  }
+}
+
+.media,
+.media-body {
+  zoom: 1;
+  overflow: hidden;
+}
+
+.media-body {
+  width: 10000px;
+}
+
+.media-object {
+  display: block;
+
+  // Fix collapse in webkit from max-width: 100% and display: table-cell.
+  &.img-thumbnail {
+    max-width: none;
+  }
+}
+
+.media-right,
+.media > .pull-right {
+  padding-left: 10px;
+}
+
+.media-left,
+.media > .pull-left {
+  padding-right: 10px;
+}
+
+.media-left,
+.media-right,
+.media-body {
+  display: table-cell;
+  vertical-align: top;
+}
+
+.media-middle {
+  vertical-align: middle;
+}
+
+.media-bottom {
+  vertical-align: bottom;
+}
+
+// Reset margins on headings for tighter default spacing
+.media-heading {
+  margin-top: 0;
+  margin-bottom: 5px;
+}
+
+// Media list variation
+//
+// Undo default ul/ol styles
+.media-list {
+  padding-left: 0;
+  list-style: none;
+}