Fixed: It cannot execute "jake" commands correctly in the Cappuccino rep...

...ository directory when it's not Apple OS.

When running "jake" commands in the repository directory, it will print:
$ jake --help
narwhal/packages/narwhal-jsc/bin/narwhal-jsc: line 33: narwhal/packages/narwhal-jsc/bin/narwhal-jscore: No such file or directory

Fixes #2181