InstData Import: split out retrieve file methods into separate modules
InstData Import: make tests use env genome-perl
InstData Import: add test for source_file_Retrieval_method to helpers; use array and uniq to get retrieval methods
InstData Import: retrieve from remote url test uses file:// protocol instead of overloading LWP::UserAgent
InstData Import: suggestions from picky pants Tom
extract methods from _check_instance_output
extract _extract_allocation_owner_id
restructure if/else block

I removed one branch:

    else {
        die $class->error_message("Unexpected condition in " . __PACKAGE__ . "::_check_instance_output");
    }

This branch was essentially unreachable due to
"_cleanup_legacy_non_software_result_data".  I did not find any log
messages containing "_check_instance_output" in the last 30 days.
simplify nested if (cleanup)
simplify nested if (validate)
extract _validate_found_allocation
extract _validate_missing_allocation
simplify if statements

instance_output is always a link here
instrument symlink removal
unlink purged and invalid allocations
check for archived allocations
CgHub Metadata: amke file size for file retrun size in bytes not kb
InstData Import: reorg retrieve classes as requested from feedback
InstData Import: add https matches to retrieve methods for remote url
do not make tarballs for symlinked data