remove unnecessary context checking which prevents scrolling if conte…

…xt default is not <c-n> or <c-p>

fixes #19

plugin/supertab.vim

@@ -367,19 +367,9 @@ function! s:SuperTab(command)
       \    b:complTypeContext == "\<c-n>"))
       return "\<c-p>"
 
-    " this used to handle call from captured keys with the longest enhancement
-    " enabled, but also must work when the enhancement is disabled.
+    " already in completion mode and not resetting for longest enhancement, so
+    " just scroll to next/previous
     elseif pumvisible() && !b:complReset
-      if b:complType == 'context'
-        exec "let contextDefault = \"" .
-          \ escape(g:SuperTabContextDefaultCompletionType, '<') . "\""
-        " if we are in another completion mode, just scroll to the next
-        " completion
-        if b:complTypeContext != contextDefault
-          return a:command == 'n' ? "\<c-n>" : "\<c-p>"
-        endif
-        return contextDefault
-      endif
       if a:command == 'n'
         return b:complType == "\<c-p>" ? "\<c-p>" : "\<c-n>"
       endif