[build] fixed a build issue (on 'ant dist') on windows.

apparently on windows symlinking requires admin rights because ?????
This can be fixed with an explicit update to group policies, which I
can't assume anybody working on lombok is going to actually do.
/bin/ln in msysgit just copies (interesting choice). I could write a mechanism
that tries /bin/ln and if not there, try <copy> instead, either in the build scripts
or in ivyplusplus, but that's way too much effort to avoid a 2MB copy. So,
for now, we just copy... if more symlinking is to be done later, we'll revisit, though.
copying is such a silly waste of time, slowing down the build for no reason.

buildScripts/compile.ant.xml

@@ -294,7 +294,7 @@ lombok.launch.AnnotationProcessorHider$ClaimingProcessor,isolating</echo>
 			</manifest>
 		</jar>
 		<delete file="release-timestamp.txt" />
-		<symlink overwrite="true" link="dist/lombok.jar" resource="lombok-${lombok.version}.jar" />
+		<copy overwrite="true" tofile="dist/lombok.jar" file="lombok-${lombok.version}.jar" />
 		<property name="lombok.dist.built" value="true" />
 	</target>