add rendering of abandoned:name instead of name=* on railway=abandoned

[Nakaner]

This fixes #114

[DerDakon]

• in case abandoned:ref is preset this should be preferred over ref, too
• this probably should also be applied to razed tracks?
• the third hunk only adds whitespace noise

[Nakaner]

@DerDakon I added support for abandoned:ref=*, razed:name=* and razed:ref=*.

[DerDakon]

There is a trailing whitespace in the first hunk.

Remove, then git commit --amend styles/standard.mapcss && git push --force

[DerDakon]

To fix the whitespace issue in the first commit:

git checkout issue-114-abandoned-name
git rebase -i HEAD~2 ## change the "pick" in the first line to "edit", then save
echo -e 'n\nn\ny' | git checkout --patch issue-114-abandoned-name styles/standard.mapcss
git rebase --continue
git push --force

I wonder if it isn't much easier to drop everything but the "text" line from all but the first statements: it's only the text line that is changed, and repeating everything else makes this harder to find out.

[Nakaner]

I fixed all the issues @DerDakon mentioned. This PR can be merged now.

[DerDakon]

• you have several instances of eval(tag("x")), which can be changed to a simple "x"
• I would keep the default text when defining the rail rendering, and just overwrite it later, this saves one markup block

And I would suggest squashing everything together, as you have many changes that live only for one commit and are then overwritten.