Apply any patches for the Recipe.

        .. versionchanged:: 0.6.0
            Add ability to apply patches from any dir via kwarg `build_dir`

def apply_patches(self, arch, build_dir=None):
        '''Apply any patches for the Recipe.

        .. versionchanged:: 0.6.0
            Add ability to apply patches from any dir via kwarg `build_dir`'''
        if self.patches:
            info_main('Applying patches for {}[{}]'
                      .format(self.name, arch.arch))

            if self.is_patched(arch):
                info_main('{} already patched, skipping'.format(self.name))
                return

            build_dir = build_dir if build_dir else self.get_build_dir(arch.arch)
            for patch in self.patches:
                if isinstance(patch, (tuple, list)):
                    patch, patch_check = patch
                    if not patch_check(arch=arch, recipe=self):
                        continue

                self.apply_patch(
                        patch.format(version=self.version, arch=arch.arch),
                        arch.arch, build_dir=build_dir)

            shprint(sh.touch, join(build_dir, '.patched'))