Modified command-line interface to handle "passphrase-style" function arguments that shouldn't be echoed to the console. There are two types: passphrase which prompts once, and new_passphrase which should be used when the command is defining a new passphrase (this type of argument prompts a second time and verifies the same value was entered both times). Did basic testing, but will test it more when I get back later today.
Merge branch 'titan' of https://github.com/BitShares/bitshares_toolkit into titan

Conflicts:
	libraries/cli/cli.cpp
Merge branch 'titan' of https://github.com/BitShares/bitshares_toolkit into titan
cleanup some minor compiler warnings