- add several commandline options to read username, password and server
from the commandline
- add help output to the commandline
- do not automatically call auth upon start-up because the user might
want to run commands like "help" which do not require to be signed in
- add -c option which, like for dash and bash allows to receive
commands via the commandline instead of standard input
- instead of having the list of commandline arguments, their handlers
and their help strings in different places, unify them in a single
array
- this allows to only change one piece of code when adding new
arguments
