add `g:clam_winpos` option
`g:clam_winpos` controls where to oepn output window.
    
        | author | Kyo Nagashima <kyo@hail2u.net> | 
    
        | date | Wed, 11 Apr 2012 04:07:03 +0900 | 
    
    
        | parents | 2b5144befdbb | 
    
        | children | c91ebd7e6560 | 
    
        | branches/tags | (none) | 
    
        | files | doc/clam.txt plugin/clam.vim | 
Changes
    
--- a/doc/clam.txt	Tue Apr 03 18:49:11 2012 -0400
+++ b/doc/clam.txt	Wed Apr 11 04:07:03 2012 +0900
@@ -87,6 +87,15 @@
 
 Default: 1 (autoreturn is on)
 
+------------------------------------------------------------------------------
+3.2 g:clam_winpos                                   *ClamConfiguration_winpos*
+
+This option control where to open output window: >
+
+    let g:clam_autoreturn = 'topleft'
+
+Default: 'vertical botright' (split vertical, open at far right)
+
 ==============================================================================
 4. License                                                       *ClamLicense*
 
--- a/plugin/clam.vim	Tue Apr 03 18:49:11 2012 -0400
+++ b/plugin/clam.vim	Wed Apr 11 04:07:03 2012 +0900
@@ -18,6 +18,10 @@
     let g:clam_autoreturn = 1
 endif " }}}
 
+if !exists('g:clam_winpos') "{{{
+    let g:clam_winpos = 'vertical botright'
+endif "}}}
+
 "}}}
 " Function {{{
 
@@ -30,7 +34,7 @@
 
     " Open the new window (or move to an existing one).
     if winnr < 0
-        silent! execute 'botright vnew ' . fnameescape(command)
+        silent! execute g:clam_winpos . ' new ' . fnameescape(command)
     else
         silent! execute winnr . 'wincmd w'
     endif