Minor style overhaul to sidebar

A number of small usability improvements / fixes, including:

* Small inconsistencies in spacing fixed
* Links now visually differentiated from headings in the menu
* Search bar actually looks right (or at least not as broken) in IE7 now
* New heart on the donate button + larger click area on the donate button!

app/assets/images/sprite.svg

@@ -17,7 +17,7 @@
    inkscape:export-filename="/Users/tmcw/src/openstreetmap-website/app/assets/images/sprite.png"
    inkscape:export-xdpi="90"
    inkscape:export-ydpi="90"
-   sodipodi:docname="New document 1">
+   sodipodi:docname="sprite.svg">
   <defs
      id="defs4" />
   <sodipodi:namedview
@@ -27,12 +27,17 @@
      borderopacity="1.0"
      inkscape:pageopacity="0.0"
      inkscape:pageshadow="2"
-     inkscape:zoom="28.421709"
-     inkscape:cx="7.0037552"
-     inkscape:cy="187.29226"
+     inkscape:zoom="8"
+     inkscape:cx="9.2822526"
+     inkscape:cy="168.88141"
      inkscape:document-units="px"
      inkscape:current-layer="layer1"
-     showgrid="true">
+     showgrid="true"
+     inkscape:window-width="1289"
+     inkscape:window-height="904"
+     inkscape:window-x="0"
+     inkscape:window-y="0"
+     inkscape:window-maximized="0">
     <inkscape:grid
        type="xygrid"
        id="grid2985"
@@ -66,10 +71,28 @@
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        style="color:#000000;fill:#999999;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:0.55720866px;marker:none;visibility:visible;display:inline;overflow:visible;enable-background:accumulate"
        id="rect3033"
-       width="7"
+       width="6.3023868"
        height="3"
-       x="679.2984"
+       x="679.99603"
        y="-530.39673"
        transform="matrix(-0.60876143,0.79335334,-0.79335334,-0.60876143,0,0)" />
+    <path
+       style="color:#000000;fill:#222222;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:1;marker:none;visibility:visible;display:inline;overflow:visible;enable-background:accumulate"
+       d="m 1,35 c 0,-1.827643 1,-4 3.75,-4 1.8276427,0 2.75,2 2.75,2 0,0 0.9223573,-2 2.75,-2 C 13,31 14,33.172357 14,35 14,40 7.5,43 7.5,43 7.5,43 1,40 1,35 z"
+       id="path3843"
+       inkscape:connector-curvature="0"
+       transform="translate(0,852.36218)"
+       sodipodi:nodetypes="sscsscs" />
+    <rect
+       style="color:#000000;fill:none;fill-opacity:1;fill-rule:nonzero;stroke:none;stroke-width:1;marker:none;visibility:visible;display:inline;overflow:visible;enable-background:accumulate"
+       id="rect3845"
+       width="15"
+       height="45"
+       x="0"
+       y="0"
+       transform="translate(0,852.36218)"
+       inkscape:export-filename="/Users/saman/work_repos/openstreetmap-website/app/assets/images/sprite.png"
+       inkscape:export-xdpi="90"
+       inkscape:export-ydpi="90" />
   </g>
 </svg>