Allow configurable version numbers for binaries

* Use system properties to set version number, maven remote repo, maven
credentials
* Remove gradle.properties as gradle prioritizes those system properties over those supplied over the command line (which is stupid)
Removing this function makes the build more fragile. Now a developer has to go to MAVEN_UPLOAD_REPO_URL and manually type in their maven path correctly. That is exactly the kind of thing that breaks really easily.

So I would suggest one of two approaches:
Approach 1 - Leave this function in and just specify the 'else' clause as System.getProperty('MAVEN_UPLOAD_REPO_URL)

Approach 2 - There is a more 'correct' approach that I don't believe existed when these files were put together. That option is to use the install task. To use that you have to include the following:

```Groovy
install {
   repositories.mavenInstaller {
      pom.version = ...
      pom.artifactId = ...
}
We would then have to set the version and artifactId using variables that we would also use in the uploadArchives task. We would ALSO have to go in and create another switch for the globalBuild script to specify if we want install or uploadArchives.

While Option 2 may be more correct, I don't think it's worth the pain. So I would suggest option 1.