Fix NERDTree opening with the wrong size. (#1008)

* Fix NERDTree opening with the wrong size.

There were two commands that seemed to be causing the NERDTree window to
open in exactly half the screen width. They are:

- silent! execute 'edit ' . t:NERDTreeBufName        in _createTreeWin()
- setlocal nobuflisted                         in _setCommonBufOptions()

These commands were reseting the width of NERDTree. The solution I chose
was to resize the window after creating the new window, and then to set
winfixwidth before setting the other common buffer options.

* Update change log and version number.

lib/nerdtree/creator.vim

@@ -189,18 +189,20 @@ function! s:Creator._createTreeWin()
         let t:NERDTreeBufName = self._nextBufferName()
         silent! execute l:splitLocation . 'vertical ' . l:splitSize . ' new'
         silent! execute 'edit ' . t:NERDTreeBufName
+        silent! execute 'vertical resize '. l:splitSize
     else
         silent! execute l:splitLocation . 'vertical ' . l:splitSize . ' split'
         silent! execute 'buffer ' . t:NERDTreeBufName
     endif
 
+    setlocal winfixwidth
+
     call self._setCommonBufOptions()
 
     if has('patch-7.4.1925')
         clearjumps
     endif
 
-    setlocal winfixwidth
 endfunction
 
 " FUNCTION: s:Creator._isBufHidden(nr) {{{1