add solarized light && minor fixes

I took the liberty of adding a “light” variant of the Solarized scheme.
Also, I added the color identifiers to the Solarized colors since that makes
the definitions easier to understand ``;-)``.

There is [another commit](https://github.com/phi-gamma/linux-vt-setcolors/commit/55fe9cdc76bc61d34cf5fe26feb88e4e8235c575)
that changes the primary foreground color  of the dark Solarized theme
to the one specified by the original Solarized palette.
I did not include this change in this pull request since the difference
seems to be intentional on your part.
If not, feel free to cherry-pick the commit.