Do not add extra %( %) in the statusline
Do not add extra %( %) in the statusline

This was used as a workaround to fix a highlighting bug, which was fixed
in Vim 7.4.1511 and therefore, we need to correctly detect that the
patch was applied and in that case skip adding those extra groups.

As a bonus, when not using those empty %( %) groups, the
skip_empty_section test will correctly handle this and therefore this
closes #1351

tschundler/dotfiles,unphased/vim-airline,chrisbra/vim-airline,yzhou61/vim-airline,rchicoli/vim-airline,HarmtH/vim-airline,tschundler/dotfiles,dalguji/vim-airline,tschundler/dotfiles,bling/vim-airline