Configliere::Commandline should not accept multiple flags as one string

[kornypoet]

This is potentially dangerous. Given a file test.rb with the following code:

#!/usr/bin/env/ruby

require 'configliere' ; Settings.use(:commandline)

Settings.define :launch_nukes, flag: 'h'
Settings.define :erase_drive, flag: 'e'
Settings.define :punch_baby, flag: 'l'
Settings.define :give_up_on_life, flag: 'p'
Settings.resolve!

p Settings

Accidentally typing -help instead of --help could lead to potentially disastrous outcomes.

# ./test.rb -help
{ :launch_nukes => true, :erase_drive => true, :punch_baby => true, :give_up_on_life => true }

Config params should be descriptive, and while shortening config to single letter flags is fun, it should be used with caution. Asking that the above invocation should fail instead of "working" isn't going too far. I argue that command line flags must be followed by a space in order to prevent the above scenario.

# ./test.rb -help
Configliere::ParserError "Detected command line flag without a space! Oh noes!"

This doesn't seem too verbose and actually clears up parsing logic.

# ./test.rb -h -e -l -p
{ :launch_nukes => true, :erase_drive => true, :punch_baby => true, :give_up_on_life => true }