Fix MASTER_SITES:
- fix LOCAL/... line to use proper directory
- re-enable sourceforge.net mirror after upstream maintainers have re-uploaded the files and promised to remember our requirements in the future. http://www.docear.org/support/forums/docear-support-forums-group3/general-feedback-questions-forum5/downloads-deliberately-hosed-again-thread236.0/#postid-837