redhat: drop calls to ldconfig in %post, %postun

we no longer install any libraries into a public library path, so
there's no longer any need to run ldconfig.
redhat: scriptlet changes

make sure the scriptlets exit with return code 0, per rpm packaging
guidelines.

redirect stderr from running the init script to stdout, rather than
trashing all output. this will show the output from init script
invocations from the scriptlets when rpm is run with the "-v" option.

add some notes about when rpm actually calls these scriptlets (upgrade
vs install, scriptlet from old rpm vs scriptlet from new rpm). see:

    https://fedoraproject.org/wiki/Packaging:ScriptletSnippets#Syntax

    https://fedoraproject.org/wiki/Packaging:ScriptletSnippets#Scriptlet_Ordering

add a %pre scriptlet that stops the daemon. this makes sure that the old
init script is used to stop the old daemon. (the existing condrestart in
the %postun scriptlet tries to stop the old daemon, if it is running,
with the new init script, which is not we want.)

add a %posttrans scriptlet that tries to start the daemon.

these changes make the rpm package behave a bit more like the deb
package. (i'm not sure if these changes are conventional for
distribution-style rpm packaging, but at the very least they shouldn't
actually be harmful.)
redhat: add a post-install support notice similar to the debian one
redhat: align init script start checks with the debian version

this aligns the check_sie_config and check_uploadkey tests with the
debian version of the init script.
redhat: silence the %preun init script invocation
doc/notes.txt: new

add some rough notes on setting up the build environments from scratch
and rebuilding the build-deps needed by the package building process.