eclipse task does not accept test resource folders

When calling the eclipse task on a project that has test resources, buildr should add the test resources' folders to the eclipse classpath. Instead, it raises the error 'undefined method `to_sym' for #<Rake::FileTask:0xb73a0694>'.

This issue is similar to issue BUILDR-106. A FileTask object is given to the path_to method, although it does not know how to handle something that is not a string or an array of symbols and strings.

This issue affects only test resources, not main resources, because of some code discrepancy in eclipse.rb