bundle: warn for --base with --all

bundle: fix error for --all with destination Before it complained about --base

bundle: fix grammar in help text

bundle: clarify help text The file might not be compressed; the interactions between -a, --base, and a named or default repository weren't clear.

cmdutil: do not duplicate stdout by makefileobj() It made output order unpredictable because two separate buffers are flushed individually. Let's use a thin wrapper that just sends close() to black hole.

cmdutil: reimplement file wrapper that disables close() There's no need to dynamically create wrappedfileobj class and define close() as lambda. Also, __iter__() was missing.