* Support SECRETS_VERBOSE env var in addition to -v
* don't use --quiet when decrypting in verbose mode
* show output of gpg encryption in verbose mode
* add tests for SECRETS_VERBOSE env var set to 0 and 1
* update changelog, reorder entries.
* add tests for 'cat' and 'hide' with SECRETS_VERBOSE=1
* tests and comments about 'changes' for #291
* add 'changes' tests, improve diagnostic
* preserve trailing newlines in diff output
* use bash trickery to preserve trailing newlines in captured text
* test 'changes' on files without newlines and when called on a non-existant file
* improve comments and variable names