Linux: Use config file for gateway settings (#1061)

- The following settings can be use on the config file:
  - verbose=[debug,info,notice,warn,err] - Logging verbosity.
  - log_file[0|1] - Enable logging to a file.
  - log_filepath=(FILE) - Log file path.
  - log_pipe=[0|1] - Enable logging to a named pipe(aka fifo).
    Use this option to view your gateway's log messages from the
    log_pipe_file (defined below).
    To do so, run the following command on another terminal:
    - $ cat "log_pipe_file"
  - log_pipe_file=(FILE)
  - syslog=[0|1] - Enable logging to syslog.
  - eeprom_file=[/etc/mysensors.eeprom]
  - eeprom_size=[1024]
- Change some mysgw parameters:
  - Added:
    - -q, --quiet:  for quiet mode, disable log messages written to the
    terminal.
  - Removed:
    - -d, --debug: removed, log messages are now enabled by default.
  - Replaced:
    - -b, --background: replaced by --daemon
- isatty() is no longer used, log messages by default are printed to
  stderr unless the gateway is started with --quiet (#1022)
- MY_LINUX_CONFIG_FILE: no longer holds the path to the eeprom file,
  but to the configuration file

initscripts/mysgw.systemd

@@ -3,7 +3,7 @@ Description=MySensors Gateway daemon
 Requires=network.target
 
 [Service]
-ExecStart=%gateway_dir%/mysgw
+ExecStart=%gateway_dir%/mysgw -q
 
 [Install]
 WantedBy=multi-user.target

initscripts/mysgw.sysvinit

@@ -17,7 +17,7 @@ PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/sbin:/usr/local/bin
 DESC="MySensors Gateway"
 NAME=mysgw
 DAEMON=%gateway_dir%/$NAME
-DAEMON_ARGS="-b"
+DAEMON_ARGS="--daemon -q"
 PIDFILE=/var/run/$NAME.pid
 SCRIPTNAME=/etc/init.d/$NAME