Attempt fix on Travis' JRuby 1.7
Revert "Remove unnecessary and complicated jar loading code that added dependency on environment variables at one time; just leave adding Cascading and Hadoop to the classpath up to the user and the build"

This reverts commit 3a7ec133dc82b721a7ca9adbc69261b758838d86.
Revert "Add dependencies to the CLASSPATH individually to fix the build; this essentially moves the dependency loading into the build and makes it simpler"

This reverts commit c559dc01c74c454a55e7fb9de8ba2349e220782d.

Conflicts:

	tasks/ant.rake