Added Notes on Gradle Outdated/Missing Dependencies

[殷啟聰]

Hi all,

Today I added some more detailed notes on what Gradle dependencies
should be upgraded or get packaged. I deleted my .gradle directory and
ran freshly the build with Gradle wrapper, then I explored every jar
files it downloaded. Please check it out:
https://wiki.debian.org/Java/Gradle

According to the list, there are quite many packages that are missing
in Debian, however not all of them are seriously needed to package.
Some are only for tests during the build, others are for plugins and
we can disable them for now. Actually we only need to package a couple
of projects, if we turn off the test during the build.

And for the outdated packages, there are lots of them but we can deal
with them quite easily. For now we can simply add a "flatDir
repository" to the build scripts and it will ignore the version when
searching for the needed jar files. After the GSoC I will start
upgrading them, for the time is limited right now.

Another thing that surprised me was that neither JaCoCo and PMD are
needed for building Gradle, and Komal and I are packaging them! So
Komal, we should hold on and focus on other things. I am so sorry for
giving us the wrong tasks. :(

Cheers and apologies,
Kai-Chung

-- 
/*
* 殷啟聰 | Kai-Chung Yan
* Full-time student of Providence University of Taiwan
* LinkedIn: <https://linkedin.com/in/seamlik>
* Blog: <seamlik.logdown.com>
*/