of a pipeline is executed in a subshell' trick, don't use co-process
(because that's verbose twice in an interactive shell profile), move
the noglob block into the while and rid the redundant +o and local.
* sync dot.mkshrc sample with FreeWRT r383
* add some stuff from src/etc/profile and contrib/samples/etc_profile
* sync the latter two with reality and shorten
* teach the user in the mksh installation instructions to install the sample
NB: the sample is also covered by the MirOS licence
