Add a 2x Glyphicons sprite sheet

Summary:
Add a 2x ("retina") sprite sheet with icons that I gave some hover/active effects. I'm just doing one sheet rather than separate 1x and 2x sheets, we can muck with it later but I don't think anyone's going to go over their bandwidth cap.

@chad, I'll put the PSD on the Dropbox too if you have a chance to give it a once-over.

Test Plan: Built menu on this, all the icons work.

Reviewers: btrahan, vrana, chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T1569

Differential Revision: https://secure.phabricator.com/D3102

webroot/rsrc/css/application/base/glyph.css

@@ -0,0 +1,73 @@
+/**
+ * @provides phabricator-glyph-css
+ */
+
+.glyph {
+  background-size: 260px auto;
+  background-image: url(/rsrc/image/glyph_sprite.png);
+}
+
+
+.glyph-profile {
+  background-position: 0 0;
+}
+
+.glyph-profile-active {
+  background-position: 0 -56px;
+}
+
+.glyph-profile:hover {
+  background-position: 0 -112px;
+}
+
+
+.glyph-settings {
+  background-position: -56px 0;
+}
+
+.glyph-settings-active {
+  background-position: -56px -56px;
+}
+
+.glyph-settings:hover {
+  background-position: -56px -112px;
+}
+
+
+.glyph-logout {
+  background-position: -112px 0;
+}
+
+.glyph-logout-active {
+  background-position: -112px -56px;
+}
+
+.glyph-logout:hover {
+  background-position: -112px -112px;
+}
+
+
+.glyph-notification {
+  background-position: -168px 0;
+}
+
+.glyph-notification-active {
+  background-position: -168px -56px;
+}
+
+.glyph-notification:hover {
+  background-position: -168px -112px;
+}
+
+
+.glyph-menu {
+  background-position: -224px 0;
+}
+
+.glyph-menu-active {
+  background-position: -224px -56px;
+}
+
+.glyph-menu:hover {
+  background-position: -224px -112px;
+}