don't rely on pkg-config for hiredis
optional hiredis
panic on startup when unable to connect to PostgreSQL
short-circuit stats in json if hiredis isn't there
autoconf: check lfcgi and lpq
introduce include/
find EQBEATS_DIR from libeqbeats
create directory structure in EQBEATS_DIR
configure: drop useless checks

they're worth nothing if we don't use the result of the tests
generate a convenient nginx.conf
eqbeats.pc for pkg-config
connect to PostgreSQL in libeqbeats
much simpler signal handling
restore /var/lib/eqbeats as default EQBEATS_DIR

it's probably not worth risking to break anything
don't let AC_CHECK_LIB override $LIBS

it creates unnecessary dependencies
https://blog.flameeyes.eu/2008/04/i-consider-ac_check_lib-harmful
hey, libpq actually has a pkgconfig file
check for some tables at initialization
check for pgcrypto
useful pg-related error messages