specfile: PREFIX is %{_prefix} instead of "/usr"

i might want to build an rpm for FreeBSD you know. /jk
while i'm not aware of any rpm-using OS with a different value,
this bit of flexibility does not hurt.
specfile: make all runs in the %build script

where it belongs.
manpage: typo
README.rest: markup changes

docutils' option list renders optargs using slanted
fixed-width font; it appears italics and fixed-width
cannot be combined using inline markup; so far i opted
to have them rendered with straight fixed-width.
this was prone to confusion re what is a placeholder
vs. an actual literal, so i'm going for italics instead.
docs have two examples

the pre-existing one comes with more prose, its config file
is produced with cat(1) (looks less pretentious than the earlier
printf(1)-based stuff, even though it's not as copy-pastable)

the new example needs some love.
tests/350-no-option-specfile done through -n

getting bogged down in implementation details (tape.expected)
is not necessary, the -n option is representative.
tests/520-firstball/.bs-update w/o duplication

same test() as in tests/fakes
tests for post-option-processing code w/o clutter

basically, the first half of bs-update.in has
bsu_configuration_processing=1, the rest of the code is
under bsu_configuration_processing=0.

the asymmetry in tests/fakes:test irks me, but it's not that much
of a deal as all tests for the option/argument-handling code use
BSU_QUIET_FAKE=1 already/anyway.
all fakes are quiet under bsu_configuration_processing=1

tests/5[015]0-*/tape.expected lose weight because they haven't
had BSU_QUIET_FAKE=1 either.
rnt updated to 14ca3728be4f117a6dd4a7b3961681b1a2ead531

    commit 14ca3728be4f117a6dd4a7b3961681b1a2ead531
    Merge: 7ca71d8 774c4dd
    Author: Roman Neuhauser <rneuhauser@suse.cz>
    Date:   Thu Apr 3 15:01:37 2014 +0200

        Merge branch 'stable-order-exitcode'

        * stable-order-exitcode:
          run-test.sh does not diff things twice
          run-test.sh outputs diffs in stable order
`bs-update -d .` under test
`bs-update -d .` supports mercurial

the test() and git() resp. hg() fakes are brittle,
i should figure out something better.
does not output the tempdir path anymore

i don't even remember when i last made use of it.
README redone as a manpage
GNUmakefile with a generalization through $(name)

makes the diffs between my hobby projects a tad smaller.
Makefile: s/mkdir -p/$(INSTALL_DIR)/g
GNUmakefile: ws changes
GNUmakefile: install target is not silent

it looks like nothing happened, esp. after non-muted 'all'.
GNUmakefile: make sure all is built before installing

prevents possible foot-shootings from running 'all' or 'check'
as root; the root-owned files in the working copy are the least
of problems that could lead to.  the install target depends on
a sentry file which is touched when 'all' succeeds.
GNUmakefile: .built target with fewer backslashes