title: Make vim's YouCompleteMe plugin recognize exuberant-ctags
body: <p>I've been trying for hours to get the YouCompleteMe plugin for vim to recognize my exuberant ctags. Everything else in YouCompleteMe appears to be working, like autocompleting functions from headers and such. I really want it to default to tag files. Below I've listed my <code>.vimrc</code> a test tags file which is located at <code>~/.vim/tags/</code></p>
  
  <p>This is my <code>testtags</code> file</p>
  
  <pre><code>!_TAG_FILE_FORMAT   2   /extended format; --format=1 will not append ;" to lines/
  !_TAG_FILE_SORTED   1   /0=unsorted, 1=sorted, 2=foldcase/
  !_TAG_PROGRAM_AUTHOR    Darren Hiebert  /dhiebert@users.sourceforge.net/
  !_TAG_PROGRAM_NAME  Exuberant Ctags //
  !_TAG_PROGRAM_URL   http://ctags.sourceforge.net    /official site/
  !_TAG_PROGRAM_VERSION   5.9~svn20110310 //
  myfunc  test.h  /^void myfunc(int a, int b);$/;"    p   language:C++
  </code></pre>
  
  <p>The <code>testtags</code> file was generated with the command <code>ctags -R --sort=1 --fields=+l --c++-kinds=+p -f testtags test.h</code></p>
  
  <p>and my <code>.vimrc</code> file here</p>
  
  <pre><code>syntax on
  filetype off
  
  set runtimepath+=~/.vim/bundle/vundle/
  call vundle#rc()
  
  Bundle 'gmarik/vundle'
  Bundle 'Valloric/YouCompleteMe'
  
  let g:ycm_collect_identifiers_from_tags_files = 1
  set tags+=~/.vim/tags/testtags
  
  filetype plugin indent on
  </code></pre>
  
  <p>The output of entering the vim command <code>:echo tagfiles()</code> is <code>['/home/jodag/.vim/tags/testtags']</code> and the command <code>:set filetype?</code> is <code>filetype=cpp</code>. This means that YCM is finding the tag files and recognizing that I'm currently editing a c++ source file but it won't show the <code>myfunc</code> completion when it press Ctrl+Space. Any help in figuring out why this is happening would be greatly appreciated!</p>