Fixed build problem when source was symlinked

[Fredrik Öhrström]

The build problem experienced by Max
was caused by the source root being symlinked.
For example the physical location was /some/where/location/build-infra/jdk7
but configure && make was run from /spaces/build-infra/jdk7 where
/spaces was a symlink to /some/where/location.

The fix was simple, change getCanonicalPath in the javac server client
to getAbsolutePath.

Thank you very much for the help in discovering the symlink problem Max!

//Fredrik