speed up AbstractJxrReport.hasSources()

The method AbstractJxrReport.hasSources( File dir ) spends a lot of time scanning .svn directories when I do my build.

If you replace the line,

else if ( currentFile.isDirectory() )

with the lines

else if ( currentFile.isDirectory()  &&
             Character.isJavaIdentifierStart(currentFile.getName().charAt(0))
)

You will speed this up.

If the first character in the directory is not a valid java identifier start, then the directory cannot contain java code. '.' is not a valid java identifier start, so .svn directories are ignored when scanning for sources.