* Add sign CLI command to sign transactions generated with the
--generate-only flag.
* Add /sign REST endpoint for Voyager support.
Redirect password prompt to STDERR to avoid messing up cli
commands output. As a rule of thumb, program's output should
always go to STDOUT, whilst errors&diagnostics go to STDERR
as per POSIX's philosophy and specs.
Now provides better error messages when the account you're sending
from has no money, or it has insufficient funds. (Avoids making
the user interpret ABCI errors)
closes#1489
* in progress
* passes current tests
* added tests and got working
* changelog and docs
* removed prints
* oops
* works!
* issue in test_cli
* number 9 number 9 number 9
* at least it does only the 9 issue now
* hallelujah it works!
* removed print statement
* rebased
* gah
