##VERSIONS:
1.0.11	- factorio 0.15 compatible
1.0.10	- better reading of accu buffer capacity (when floating point number...)
1.0.9	- increase accumulators buffer size to support longer nights (multiply by day_length_multiplier)
1.0.8	- add an interface to enable/disable mod :
			/c remote.call( "daynight", "on" )
			/c remote.call( "daynight", "off" )
		- add an interface to change multiplier :
			/c remote.call( "daynight", "multi", 4 )
1.0.7	- factorio 0.14 compatible
1.1.6	- check all surfaces, and then unify day and night multipliers to simplify calculations and differences between surfaces. INtroduce config.lua. Default with x4	- 28 mins cycle.
1.1.4	- relaxes frequency, adds always_day checking
1.1.3	- update by Binbinhfr for factorio 0.13.x, published on portal
1.1.2	- update by Mikenlott
1.1.0	- update by Vizzy
1.0.0	- original release by Dark