Use binary encoding for child_process.exec(): it allows to retrieve b…

…inary

files content from history.

src/git.coffee

@@ -13,7 +13,7 @@ module.exports = Git = (git_dir, dot_git) ->
     args    ?= []
     args     = args.join " " if args instanceof Array
     bash     = "#{Git.bin} #{command} #{options} #{args}"
-    exec bash, {cwd: git_dir}, callback
+    exec bash, {cwd: git_dir, encoding:'binary'}, callback
     return bash