Repositories, AdoptOpenJDK and github

[Johan Vos]

Hi,

I did 2 things:
* I talked to the fine and great people at AdoptOpenJDK (
https://adoptopenjdk.net/) and they are happy to have their build farm
being used to create OpenJFX modules (including the native libraries). We
are currently looking at the scripts that are being used for syncing and
building OpenJDK, and the sync script is already in place.

* While on the subject of syncing, I used a similar script to create and
sync a mirror of OpenJFX at github. It is now available at
https://github.com//javafxports/openjdk-jfx
(planning to sync at least a few times a day, by pulling in the latest
changes from OpenJFX).

This is a sandbox repository, and it won't be used to automatically
generate builds from.
If you want to play with the source, add features, fix bugs, work on
documentation, you can fork this repository. If you want to contribute, you
can create PR's. The idea is that OpenJFX committers can merge PR's in this
repository. That doesn't automatically upstream them to OpenJFX, but if an
OpenJFX committer agrees with your PR, he can use the existing webrev
system at OpenJFX to start the process of merging it into OpenJFX.
Since a PR might be used to merge code in OpenJFX, it is required that you
have an OCA (see
http://www.oracle.com/technetwork/community/oca-486395.html for
more info).

In summary, the flow might look like this:
1. Developer forks the github repo, enhances it, and creates a PR.
2. He discusses it with a committer, and eventually the PR is accepted.
3. The committer creates a webrev and an OpenJFX Reviewer reviews.
4. If accepted, that code is merged into OpenJFX.
5. The AdoptOpenJFX build farm creates a build including that new code.

Note that this creates additional work for the current OpenJFX committers
(including myself). Please be patient and helpful if you raise a PR. I
expect PR's to be well tested and documented. A PR is not just an idea with
some code being thrown over the wall.

JavaFX has been Open Source for a very long time. By having the code also
as a github mirror, I hope we can attract more people, and get more
attention to this great project, while preserving the high quality that is
really needed to keep JavaFX aligned with the high standards that people
expect from the Java platform.

Thanks,

- Johan