RFR: 7903135: Correct license file [v4]

[Dmitry Bessonov]

> The JT Harness repository doesn't have a LICENSE file.
> It contains `legal/license.txt`.
> We need to place a proper LICENSE file to the repository root.

Dmitry Bessonov has updated the pull request incrementally with two additional commits since the last revision:

 - ReleaseNotes-jtharness.html: updating link to the new proper GPL v2 LICENSE
 - build.xml: copying LICENSE file to the distro

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

Changes:
  - all: https://git.openjdk.java.net/jtharness/pull/26/files
  - new: https://git.openjdk.java.net/jtharness/pull/26/files/7099448f..4ab6db73

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jtharness&pr=26&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jtharness&pr=26&range=02-03

  Stats: 4 lines in 2 files changed: 1 ins; 1 del; 2 mod
  Patch: https://git.openjdk.java.net/jtharness/pull/26.diff
  Fetch: git fetch https://git.openjdk.java.net/jtharness pull/26/head:pull/26

PR: https://git.openjdk.java.net/jtharness/pull/26