Issue #72 still reproduces

[fkawa-play]

I tried to use it after solved #72, however, it still reproduces following error:

 % vi ~/.vimrc
Error detected while processing function <SNR>52_DefineSign:
line    6:
E239: Invalid sign text: ║E
Press ENTER or type command to continue

Then, I added let g:quickfixsigns_sign_may_use_double = 0 and it is prevented. However, If I set this parameter, WARNING sign can be changed '╠'. Currently, I just applied following patch:

 % git diff --no-prefix

diff --git plugin/quickfixsigns.vim plugin/quickfixsigns.vim
index 8475598..6446100 100755
--- plugin/quickfixsigns.vim
+++ plugin/quickfixsigns.vim
@@ -295,8 +295,8 @@ endf

 call s:DefineSign('QFS_CURSOR', '-', 'Question', 'cursor')
 call s:DefineSign('QFS_DUMMY', '.', 'NonText', '')
-call s:DefineSign('QFS_QFL', &enc ==? 'utf-8' ? '╠' : '*', 'WarningMsg', 'qfl')
-call s:DefineSign('QFS_LOC', &enc ==? 'utf-8' ? '├' : '>', 'Special', 'loc')
+call s:DefineSign('QFS_QFL', (g:quickfixsigns_sign_may_use_double && &enc ==? 'utf-8' ? '╠' : '*'),'WarningMsg', 'qfl')
+call s:DefineSign('QFS_LOC', (g:quickfixsigns_sign_may_use_double && &enc ==? 'utf-8' ? '├' : '>'), 'Special', 'loc')

 for s:char in split(g:quickfixsigns_list_types, '\zs')
     call s:DefineSign('QFS_QFL_'. s:char, (g:quickfixsigns_sign_may_use_double && &enc ==? 'utf-8' ? '║' : '*') . s:char, 'WarningMsg', 'qfl_'. s:char)