Removed 'contained' constraint from 'this' keyword highlight

`this` can be used outside of any other block and thus needs to be highlighted
there.

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Actions:
  * Fix #610

Author: jfelchner

Diff for: syntax/javascript.vim

@@ -92,7 +92,7 @@ exe 'syntax keyword jsReturn    return contained '.(exists('g:javascript_conceal
 exe 'syntax keyword jsUndefined undefined        '.(exists('g:javascript_conceal_undefined') ? 'conceal cchar='.g:javascript_conceal_undefined  : '')
 exe 'syntax keyword jsNan       NaN              '.(exists('g:javascript_conceal_NaN')       ? 'conceal cchar='.g:javascript_conceal_NaN        : '')
 exe 'syntax keyword jsPrototype prototype        '.(exists('g:javascript_conceal_prototype') ? 'conceal cchar='.g:javascript_conceal_prototype  : '')
-exe 'syntax keyword jsThis      this   contained '.(exists('g:javascript_conceal_this')      ? 'conceal cchar='.g:javascript_conceal_this       : '')
+exe 'syntax keyword jsThis      this             '.(exists('g:javascript_conceal_this')      ? 'conceal cchar='.g:javascript_conceal_this       : '')
 exe 'syntax keyword jsSuper     super  contained '.(exists('g:javascript_conceal_super')     ? 'conceal cchar='.g:javascript_conceal_super      : '')
 
 " Statement Keywords