patchbomb: Support initial in-reply-to header This allows follow-up/revised patches to appear properly threaded in mail readers and in the archives, reducing noise.

profiling: Adding support for kcachegrind output format, using lsprofcalltree

profiling: Adding a profiling.format config variable Allows defining other output formats for profiling. If an invalid format is given, output a warning and ignore it. For now, only the standard 'text' value is supported.