RFR: 8234704: Fix attribution in libxslt.md

[Kevin Rushforth]

We discovered three minor differences between the `libxslt.md` file and the libxslt-1.1.34 source bundle:

1. The copyright years didn't match the source

2. The following line was missing:
Licence for libxslt except libexslt

3. The terms currently lists `BLFS` rather than `DANIEL VEILLARD` in one place.

Note to reviewers:

I pushed this in two commits as an aid to reviewing it (as with any other PR, it will be squashed during integration). The first commit just fixes the above three issues without any reformatting of the lines. The second commit has no changes in the content itself, but re-wraps the lines to match the source.

----------------

Commits:
 - 07be5f50: Reformat to match format of original source -- no changes in content
 - 68adb259: 8234704: Fix attribution in libxslt.md

Changes: https://git.openjdk.java.net/jfx/pull/52/files
 Webrev: https://webrevs.openjdk.java.net/jfx/52/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8234704
  Stats: 20 lines in 1 file changed: 2 ins; 0 del; 18 mod
  Patch: https://git.openjdk.java.net/jfx/pull/52.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/52/head:pull/52

PR: https://git.openjdk.java.net/jfx/pull/52