- move "MD instructions on setting up boot media"
from common/xfer with messy mdoc .if conditionals
into MD xfer files so that developers can see
what contents are missing or obsolete and should be
written or updated
- remove some useless MD description for maintainability

XXX: still a bunch of unmaintained .if \n [${MACHINE}] in common files

branches: 1.2.34;
major terraform (this is MUCH more than a rototill :-), including:
- update for 1.5 (still more MD stuff to check)
- use new macros in ../common/macros as appropriate
- introduce some CONSISTENCY between the various ports' install docs
- use various mdoc macros as appropriate, including .Li, .Pa, .Sy, and .Ic.
- migrate more stuff into ../common/*
- whitespace cleanup
- lots of other little things i'm sure...

branches: 1.1.4;
add notes for hpcmips.

Sync to HEAD as of 20001101 03:43 GMT [lukem]:
Complete rework of install notes for 1.5 from several authors.

Sync with HEAD.