Properly pad aliases for option usage

Options can have aliases of arbitrary length, not just just a dash with
a single letter. When printing the usage for options we should look at
the actual formatted options instead of multiplying by the number 4 (the
size of a single option: `-t, `).

__Before (examples)__
```console
Usage:
  thor my_counter N [N]

Options:
  -t, [--third=THREE]   # The third argument
                        # Default: 3
          [--fourth=N]  # The fourth argument
  z, [--simple=N]
  y, r, [--symbolic=N]
```

__After (examples)__
```console
Usage:
  thor my_counter N [N]

Options:
  -t,   [--third=THREE]  # The third argument
                         # Default: 3
        [--fourth=N]     # The fourth argument
  z,    [--simple=N]
  y, r, [--symbolic=N]
```

Author: p8

lib/thor/base.rb

@@ -558,8 +558,7 @@ def print_options(shell, options, group_name = nil)
         return if options.empty?
 
         list = []
-        padding = options.map { |o| o.aliases.size }.max.to_i * 4
-
+        padding = options.map { |o| o.aliases_for_usage.size }.max.to_i
         options.each do |option|
           next if option.hide
           item = [option.usage(padding)]

lib/thor/parser/option.rb

@@ -93,10 +93,14 @@ def usage(padding = 0)
         sample << ", [#{dasherize('no-' + human_name)}]" unless (name == "force") || name.start_with?("no-")
       end
 
+      aliases_for_usage.ljust(padding) + sample
+    end
+
+    def aliases_for_usage
       if aliases.empty?
-        (" " * padding) << sample
+        ""
       else
-        "#{aliases.join(', ')}, #{sample}"
+        "#{aliases.join(', ')}, "
       end
     end
 

spec/base_spec.rb

@@ -139,8 +139,9 @@ def hello
     end
 
     it "use padding in options that do not have aliases" do
-      expect(@content).to match(/^  -t, \[--third/)
-      expect(@content).to match(/^          \[--fourth/)
+      expect(@content).to match(/^  -t,   \[--third/)
+      expect(@content).to match(/^        \[--fourth/)
+      expect(@content).to match(/^  y, r, \[--symbolic/)
     end
 
     it "allows extra options to be given" do