derivepassphrase wish no-strict-compatibility-mode

Wish details: Provide a mode of operation forfeiting strict compatibility

Class	wish	This is a request for an enhancement.
Priority	medium	This should be fixed one day.
Difficulty	fun	Just needs tuits, and not many of them.
Present-in	0.4.0 0.5 0.5.1 0.5.2 0.6

derivepassphrase vault contains multiple options (e.g., --modern-editor-interface) that change its behavior in a manner incompatible with vault(1), but which the user may nevertheless want to select because the vault(1) behavior is surprising, inconsistent, etc.

Because of our commitment to backwards compatibility with vault(1), such divergent behavior must be requested separately for each call to derivepassphrase. Currently, this means manually adding the respective options to each command-line invocation.

Alternatively, we could add configuration settings corresponding to those behavior-changing options, and provide a single option (e.g., --no-strict-compatibility) that instructs derivepassphrase to honor those configuration settings, even if the resulting behavior differs from vault(1). This alleviates the cognitive load on the user – they only need to remember the --no-strict-compatibility options, not their specific collection of behavior change options. It is also easily extendable to other passphrase derivation schemes and their original implementations.

Therefore, implement a common option to turn off strict command-line compatibility with vault(1) (and other original implementations of passphrase derivation schemes) and to honor behavioral change settings specified in the configuration.