RFR: 8017047: Can't use --with-java-devtools and --with-devkit at the same time

[Erik Joelsson]

Open part of this review:

There is an artificial limitation put into configure that prevents usage 
of options --with-devkit and --with-tools-dir at the same time. The 
reason was probably because they could potentially be conflicting. This 
patch removes this check and makes them work together, both ending up on 
the search path for tools (with --with-tools-dir ending up ahead of devkit).

I also stumbled on some dead code that was causing warnings to be 
printed when using --with-devkit and decided to remove that while 
touching that option anyway.

http://cr.openjdk.java.net/~erikj/8017047/webrev.root.01/

/Erik