Add another TODO item
Add dependency on Thud
Use thud_unindent instead of carton_unindent
Remove unused carton_arr_copy
Use thud_backtrace instead of carton_backtrace
Use thud_abort* instead of carton_abort
Use thud_assert instead of carton_assert
Use thud_arr_* instead of carton_arr_*
Remove unused carton_is_valid_var_name
Rename carton_is_valid_fs_name->carton_is_fs_name
Remove an obsolete TODO from source
Use Thud strict mode

Use Thud strict mode, adjust to noclobber attribute used by it.
Quote backticks in array initializers

Quote backticks used in array initializers as they might be subject to
pathname expansion.
Handle package release dist tags in tests

Make tests account for the possible dist tags appearing in package
release strings when checking for package presence.