Add filename format customization to Powerline

gistfile1.txt

diff --git a/powerline/distinguished.vim b/powerline/distinguished.vim
index a2b52a9..6d14142 100644
--- a/powerline/distinguished.vim
+++ b/powerline/distinguished.vim
@@ -12,6 +12,13 @@ function! Stl_GetBranch(branch_symbol) " {{{
 
        return ret
 endfunction " }}}
+function! Stl_GetPreferredFilenameFormat() " {{{
+    if ! exists('g:Powerline_filename_format')
+        return expand('%:t')
+    endif
+
+    return expand(g:Powerline_filename_format)
+endfunction " }}}
 function! Stl_GetSyntaxErrors(line_symbol) " {{{
        if ! exists('g:syntastic_stl_format')
                " Syntastic hasn't been loaded yet
diff --git a/powerline/distinguished/00-default.vim b/powerline/distinguished/00-default.vim
index 359676e..9d57639 100644
--- a/powerline/distinguished/00-default.vim
+++ b/powerline/distinguished/00-default.vim
@@ -22,7 +22,7 @@ call Pl#Statusline(
                        \ Pl#HiInsert(    Pl#FG(196)),
                        \ Pl#HiNonCurrent(Pl#FG( 88))
                        \ ),
-               \ Pl#Segment(" %t ",
+               \ Pl#Segment(" %{Stl_GetPreferredFilenameFormat()} ",
                        \ Pl#HiCurrent(   Pl#FG(231), Pl#Attr('bold')),
                        \ Pl#HiInsert(    Pl#FG(231), Pl#Attr('bold')),
                        \ Pl#HiNonCurrent(Pl#FG(245), Pl#Attr('bold'))