Parse the java classpaths with a newline delimiter

Seems Mathworks started adding comments (tested on R2013a) to the classpath.txt file of the form `# comments with spaces`. When PsychtoolboxPostInstallRoutine adds PsychJava to the classpath, it `textscan`s the input which by default breaks on whitespace. This results in an output that has newlines injected where ever there was whitespace originally.