version 0.3.4

Changes since 0.3.3:

• b3sum now supports the --check flag. This is intended to be a drop-in replacement for e.g. md5sum --check from Coreutils. The behavior is somewhat stricter than Coreutils with respect to invalid Unicode in filenames. For a complete description of how --check works, see the file b3sum/what_does_check_do.md.
• To support the --check feature, backslashes and newlines that appear in filenames are now escaped in the output of b3sum. This is done the same way as in Coreutils.
• To support --check interoperability between Unix and Windows, backslashes in filepaths on Windows are now replaced with forward slashes in the output of b3sum. Note that this is different from Coreutils.