RFR: JDK-8241463 Move build tools to respective modules

[Magnus Ihse Bursie]

The build tools (small java tools that are run during the build to 
generate source code, or data, needed in the JDK) have historically been 
placed in the "make" directory. This maybe made sense long time ago, but 
does not do so anymore.

Instead, the build tools source code should move the the module that 
needs them. For instance, compilefontconfig should move to java.desktop, 
etc.

There are multiple reasons for this:

* Currently we build *all* build tools at once, which mean that we 
cannot compile java.base until e.g. the compilefontconfig tool is 
compiled, even though it is not needed.

* If a build tool, e.g. compilefontconfig is modified, all build tools 
are recompiled, which triggers a rebuild of more or less the entire JDK. 
This makes development of the build tools unnecessary tedious.

* When the build tools are modified, the group owning the corresponding 
module is the proper review instance, not the build team. But since they 
reside under "make", the review mails often include build-dev, but this 
is mostly noise for us. With this move, the ownership is made clear.

In this patch, I have not modified how and when the build tools are 
compiled, but this shuffle is the prerequisite for continuing with that 
in a follow-up patch.

I have also moved the build tools to the org.openjdk.buildtools.* 
package name space (inspired by Skara), instead of the strangely named 
build.tools.* name space.

A few build tools are not moved in this patch. Two of them, 
charsetmapping and cldrconverter, are shared between two modules. (I 
think they should move to modules nevertheless, but they need some more 
thought to make sure I do this right.) The rest are tools that are 
needed for the build in general, like linking or javadoc support. I'll 
move this to a better location too, but in a separate patch.

Bug: https://bugs.openjdk.java.net/browse/JDK-8241463
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8241463-move-build-tools-to-modules/webrev.01

/Magnus