logos: optimise SVG images

The main motivation for this change was unnecessary double point in the
icon path.  The top point of the right corner of the icon are in fact
two separate points.  I’ve used Inkscape’s ‘Join selected nodes’
function to merge them.  I’ve then rounded coordinates in the path to
two decimal points (again using Inkscape) and finally using a simple
regex eliminate unnecessary spaces in the `d` attribute.

Working on that I've noticed that the clip paths don’t actually do
anything: the paths do not go over the clip paths.  I’ve thus removed
the clip paths.

The styles for the path were over-specified.  `fill-opacity: 1`,
`fill-rule: nonzero` and `stroke: none` are all initial values of the
properties, so I’ve stripped them out.

Finally, in the Logo images, the `width` attribute was specified without
a unit.  To match the `height` and the Icon images, I’ve added `pt`
unit.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>

Author: mina86