Command-line option to install as Local System

Added the ability to install the service using the Local System account
from the command-line.
This also requires an update to the docs at:
http://topshelf.readthedocs.org/en/latest/overview/commandline.html to
include the new parameter.
Setting ServiceBase.ServiceName so fatal errors make it to the Event Log
Updated docs for new command-line parameter

Added the new parameter for installing as Local System account to the
docs.
Fixed numbering not corresponding to the lines
Fixed log message for processing custom command.
Changed to use InfoFormat
Added StartTimeOut and StopTimeOut properties to HostSettings

to configure timeout values of StartService and StopService methods of HostEnvironment.
Update index.rst
Update NLog to 3.1.0 and resolve "obsolete" warnings