Merge branch 'ks/config-file-stdin'

"git config" learned to read from the standard input when "-" is given as the value to its "--file" parameter (attempting an operation to update the configuration in the standard input of course is rejected). * ks/config-file-stdin: config: teach "git config --file -" to read from the standard input config: change git_config_with_options() interface builtin/config.c: rename check_blob_write() -> check_write() config: disallow relative include paths from blobs