css: chromium: fix glyph misalignment

The glyphs were not vertically centered (the 'top' property was
ignored).
bugfix: make carousel items slide in Chromium

Incidentally, removing this line has no effect in Firefox. That is, it
was dead code in Firefox already.

Versions:

  - Chromium 39.0.2171.71
  - Mozilla Firefox 34.0.5
carousel: fix margins of left/right hand icons

We previously relied on `text-align` to place the hand icons (for
clicking to go to prev/next carousel item); we now use proper
non-text-related CSS for positioning the icons properly.
css: body: adjust padding
css: carousel-indicators: use wrapper

The idea here is to make them like the left/right hand icons (those
glyphicons are wrapped inside several layers of divs; we do the same
here by introducing a wrapper div).
css: remove dead code
carousel: make images scale with window size

The key is to give the '.carousel-inner' div the 'overflow: visible'
property, to prevent clipping of children that grow beyond the size of
the carousel (500px height).
css: remove dead code
css: left/right controls: wider clickable area
carousel-indicators: add some spacing
carousel: bigger left/right icons
carousel: fix hand positioning in Chromium

Without this change, chromium simply ignores the 'top: 50%' value.
Firefox does not care either way.

Versions:

  - Chromium 39.0.2171.71
  - Mozilla Firefox 34.0.5