Update TODO
Improve default value of g:Easymotion_keys

- Use qwerty keys layout by default and this is intuitive and easy to
  type
- Remove uppear case letter because to press Shit is pain and EasyMotion
  shows two label if there are a lot of matches, so it's little problem
  to reduce g:Easymotion_keys
- EasyMotion use last keys as a first key of two label, so I moved `f`,
  `j`, and `;` to last
Implement g:EasyMotion_space_jump_first

Description: If you set this value 1, you can jump to first match by
             pressing space when prompt target label. <Space> key
             version of g:EasyMotion_enter_jump_first
Default: 0
Modify should_use_smartcase to should_case_sensitive

Take into account &ignorecase and &smartcase for n key find motion to be
consistent with vim default search
Fix default key of `s` didn't work

Remove obsolete mapping `S`
Merge branch 'improve/default' into master #85