Allowing to create hold invoices just by providing a payment hash
instead of the preimage right from the beginning allows for additional
use cases where the recipient doesn't have access to the preimage when
creating the invoice.
Notably verifymessage and decrypt(message) were silently ignoring trailing garbage
or inserted non-base64 characters present in signatures/ciphertext.
(both the CLI commands and in the GUI)
I think it is much cleaner and preferable to treat such signatures/ciphertext as invalid.
In fact I find it surprising that base64.b64decode(validate=False) is the default.
Perhaps we should create a helper function for it that set validate=True and use that.
This allows plugins to document the commands they add.
The docstring is parsed as a regular expression:
arg:<type>:<name>:<description>\n
Types are defined in commands.arg_types.
Note that this commit removes support for single letter
shortcuts in command options.
If a command is not properly documented, a warning is issued
with print(), because no logger is available at this point.
This is most useful if the user wants to import a significant number of keys,
as every invocation of `importprivkey` results in rewriting the wallet file to disk.
The API of "importprivkey" is left unchanged for the single privkey case.
