First version of buffertag.vim extension. * Enable: `let g:ctrlp_extensions = ['buffertag']` * Command: ':CtrlPBufTag' * Options: + g:ctrlp_buftag_ctags_bin + g:ctrlp_buftag_systemenc + g:ctrlp_buftag_types
* Close #44 * Add help tags for extension's commands. Issue #43. * Folding tweak.
* New extensions for searching tag and quickfix. * Option to update the results lazily. Close #37.