Previously, the Levenshtein distances to most commands were wrongly
calculated due to a big shortcut. This might be included in the original
code for the performance sake, but I'm not sure that's something we should
take over accuracy in Rails.

Before
'foo' to 'assets'                  #=> 3
'foo' to 'controller'              #=> 3
'foo' to 'generator'               #=> 3
'foo' to 'helper'                  #=> 3
'foo' to 'integration_test'        #=> 3
'foo' to 'jbuilder'                #=> 3
'foo' to 'job'                     #=> 2
'foo' to 'mailer'                  #=> 3
'foo' to 'migration'               #=> 3
'foo' to 'model'                   #=> 3
'foo' to 'resource'                #=> 3
'foo' to 'resource_route'          #=> 3
'foo' to 'scaffold'                #=> 3
'foo' to 'scaffold_controller'     #=> 3
'foo' to 'task'                    #=> 4
'foo' to 'active_record:migration' #=> 3
'foo' to 'active_record:model'     #=> 3
'foo' to 'coffee:assets'           #=> 3
'foo' to 'css:assets'              #=> 3
'foo' to 'css:scaffold'            #=> 3
'foo' to 'erb:controller'          #=> 3
'foo' to 'erb:mailer'              #=> 3
'foo' to 'erb:scaffold'            #=> 3
'foo' to 'js:assets'               #=> 3
'foo' to 'scss:assets'             #=> 3
'foo' to 'scss:scaffold'           #=> 3
'foo' to 'test_unit:controller'    #=> 3
'foo' to 'test_unit:generator'     #=> 3
'foo' to 'test_unit:helper'        #=> 3
'foo' to 'test_unit:integration'   #=> 3
'foo' to 'test_unit:job'           #=> 3
'foo' to 'test_unit:mailer'        #=> 3
'foo' to 'test_unit:model'         #=> 3
'foo' to 'test_unit:plugin'        #=> 3
'foo' to 'test_unit:scaffold'      #=> 3

After
'foo' to 'assets'                  #=> 6
'foo' to 'controller'              #=> 8
'foo' to 'generator'               #=> 8
'foo' to 'helper'                  #=> 6
'foo' to 'integration_test'        #=> 15
'foo' to 'jbuilder'                #=> 8
'foo' to 'job'                     #=> 2
'foo' to 'mailer'                  #=> 6
'foo' to 'migration'               #=> 8
'foo' to 'model'                   #=> 4
'foo' to 'resource'                #=> 7
'foo' to 'resource_route'          #=> 12
'foo' to 'scaffold'                #=> 6
'foo' to 'scaffold_controller'     #=> 16
'foo' to 'task'                    #=> 4
'foo' to 'active_record:migration' #=> 21
'foo' to 'active_record:model'     #=> 17
'foo' to 'coffee:assets'           #=> 12
'foo' to 'css:assets'              #=> 10
'foo' to 'css:scaffold'            #=> 10
'foo' to 'erb:controller'          #=> 12
'foo' to 'erb:mailer'              #=> 10
'foo' to 'erb:scaffold'            #=> 10
'foo' to 'js:assets'               #=> 9
'foo' to 'scss:assets'             #=> 11
'foo' to 'scss:scaffold'           #=> 11
'foo' to 'test_unit:controller'    #=> 18
'foo' to 'test_unit:generator'     #=> 18
'foo' to 'test_unit:helper'        #=> 16
'foo' to 'test_unit:integration'   #=> 20
'foo' to 'test_unit:job'           #=> 12
'foo' to 'test_unit:mailer'        #=> 16
'foo' to 'test_unit:model'         #=> 14
'foo' to 'test_unit:plugin'        #=> 16
'foo' to 'test_unit:scaffold'      #=> 16

Besides that, the conjunction "or" of the message now appears only between
the last two suggestions.

Signed-off-by: Yuki Nishijima <mail@yukinishijima.net>