Backtrace filtering does not work correctly with chef-solo

Backtrace filtering in the resource failure and compile error inspectors assumes cookbooks will be located in file_cache_path, which is incorrect for chef-solo. Using cookbook_path instead should give the correct result on chef-client and chef-solo.

Further, when creating the regex filter for the backtrace, Regep.escape should be used to avoid problems with regex-significant characters occuring in filenames.