HR bugfix - #186831

https://netbeans.org/bugzilla/show_bug.cgi?id=186831

Description: Project build (of J2SE project, Web project, EjbJar project 
and AppClient project) fails when the following conditions are 
satisfied: processorpath is empty, running on Windows, non-default 
platform selected, source level >= 1.6. The empty processorpath 
parameter is not correctly passed to the forked process. The fix is to 
add an empty directory on the processorpath when building.

Impact: the project cannot be built, can be workarounded by adding an 
empty directory/jar on processorpath.

Risk assessment: low. The fix ensures that the processorpath always 
contains at least one element during the build.

Reviewed by Tomas Zezula and Peter Pis.

http://hg.netbeans.org/main/rev/a5021627ce7a

Thanks for review,
     Jan