Description of problem:

  At present, it's very difficult at runtime to determine several
  compile time options in a cross platform way.

  eg: Which directory is the run time state stored in?
      Where directory were the library files installed to?

  and so on.

  It would be useful to have glusterd/glusterfsd be able to
  display these at runtime, maybe using an approach similar to
  'httpd -V'.  This is the output from 'httpd -V' as example:

    $ httpd -V
    Server version: Apache/2.2.15 (Unix)
    Server built:   Mar 20 2014 06:21:02
    Server's Module Magic Number: 20051115:25
    Server loaded:  APR 1.3.9, APR-Util 1.3.9
    Compiled using: APR 1.3.9, APR-Util 1.3.9
    Architecture:   64-bit
    Server MPM:     Prefork
      threaded:     no
        forked:     yes (variable process count)
    Server compiled with....
     -D APACHE_MPM_DIR="server/mpm/prefork"
     -D APR_HAS_SENDFILE
     -D APR_HAS_MMAP
     -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
     -D APR_USE_SYSVSEM_SERIALIZE
     -D APR_USE_PTHREAD_SERIALIZE
     -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
     -D APR_HAS_OTHER_CHILD
     -D AP_HAVE_RELIABLE_PIPED_LOGS
     -D DYNAMIC_MODULE_LIMIT=128
     -D HTTPD_ROOT="/etc/httpd"
     -D SUEXEC_BIN="/usr/sbin/suexec"
     -D DEFAULT_PIDLOG="run/httpd.pid"
     -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
     -D DEFAULT_LOCKFILE="logs/accept.lock"
     -D DEFAULT_ERRORLOG="logs/error_log"
     -D AP_TYPES_CONFIG_FILE="conf/mime.types"
     -D SERVER_CONFIG_FILE="conf/httpd.conf"


Version-Release number of selected component (if applicable):

  Would be good to get this into 3.6.x, but if not, then 3.7.x.