git gfa diff integration

[revol@me ~/devel/gfalist/foo]$ git config --local -l
core.repositoryformatversion=0
core.filemode=true
core.bare=false
core.logallrefupdates=true
diff.gfa.textconv=/home/revol/devel/gfalist/ons-0.01.a/gfalist
[revol@me ~/devel/gfalist/foo]$ cat .gitattributes
*.gfa diff=gfa
[revol@me ~/devel/gfalist/foo]$ git log
commit 14e467e9774c116c2204127b124dc458d3761e0b
Author: François Revol <revol@free.fr>
Date:   Sun Mar 10 04:25:19 2013 +0100

    empty gfa file
[revol@me ~/devel/gfalist/foo]$ cp ../tests/quit0.gfa test.gfa
[revol@me ~/devel/gfalist/foo]$ git diff
diff --git a/test.gfa b/test.gfa
index 9dfbbd6..b8612d8 100644
--- a/test.gfa
+++ b/test.gfa
@@ -0,0 +1 @@
+QUIT 0
[revol@me ~/devel/gfalist/foo]$ cp ../tests/litchi.gfa test.gfa
[revol@me ~/devel/gfalist/foo]$ git diff
diff --git a/test.gfa b/test.gfa
index 9dfbbd6..ba63659 100644
--- a/test.gfa
+++ b/test.gfa
@@ -0,0 +1,14490 @@
+$m320000
+DEFFLT "a-b"
+'
+~FRE(0)
+IF FRE()<160000
+  ~FORM_ALERT(1,"[1][Insufficient or fragmented memory. ][ Quit ]")
+  QUIT 0
+ELSE
+  order$=CHAR{ADD(BASEPAGE,128)}
+  '
+  init_start
+  init_rsc
+  @font_init
+  @load_options
+  init_end
+  main
+ENDIF
+'
...