RFR: 8249777: build.gradle: project.version should not contain time stamps [v2]

[Kevin Rushforth]

> The addMavenPublication method sets the `project.version` to `$MAVEN_VERSION`, where project is base, graphics,
> controls, etc. When doing an ordinary "developer" build, this property contains the time stamp . This is causing
> problems with the NetBeans gradle plugin not being able to determine the dependencies between the projects (modules).
> We haven't noticed this bug before now, because we suppress the creation of the individual project jar files, but if we
> were creating them, we would have the problem that each time we ran gradle, it would generate a new
> `project-$version.jar` file with a different time stamp each time the build was run.  The setting of
> `project.version=$MAVEN_VERSION` is only used by the maven "publish" tasks, which isn't done for developer builds nor
> for most productions builds.  The proposed solution is to add a new boolean `MAVEN_PUBLISH` flag, which will default to
> `false`. This flag will qualify the setting of the `MAVEN_VERSION` property and the configuration of the maven
> publishing tasks. After this change, it will be necessary to run gradle with `-PMAVEN_PUBLISH=true` in order to run the
> maven publishing tasks.

Kevin Rushforth has updated the pull request incrementally with one additional commit since the last revision:

  Remove unised mavenPublish property from graphics project

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

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/270/files
  - new: https://git.openjdk.java.net/jfx/pull/270/files/592ad650..1c077ec5

Webrevs:
 - full: https://webrevs.openjdk.java.net/jfx/270/webrev.01
 - incr: https://webrevs.openjdk.java.net/jfx/270/webrev.00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/270.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/270/head:pull/270

PR: https://git.openjdk.java.net/jfx/pull/270