New Config Engine - 'valid' helper
Improve TestUtils to return hashref when needed
New Config Engine - 1) export 'seen' 2) implement 'type' for options
Config for 'upload-file' command
New Config Engine - test for should allow to define option types with empty type + misc test fixes
Move sanity_relative_filename to Utils.pm
is_relative_filename helper added
upload file feature - validation of set-rel-filename implemented
upload_file - test cases with relative filename, introduce new custom option 'relfilename'
upload_file - some improvements to validations
more validations for filename option
fix broken tests after we start validating 'dir'
upload_file - file uploading should work without absolute filenames + implement upload for STDIN
upload_file - config should return 'relfilename' custom value  in all cases
upload_file - upload file command implemented
upload_file - disallow multiversioning for now
upload_file - max-file-size option implemented
upload-file - check for zero-size STDIN upload
upload_file - option renamed to check-max-file-size
upload-file - documentation