Call rendering, if not already done

Then freeze the template

This method is only required in corner-cases since rendering is automatically called when needed.

Property definitions

template $ Template :: force_render
	# Call rendering, if not already done
	# Then freeze the template
	#
	# This method is only required in corner-cases since
	# `rendering` is automatically called when needed.
	fun force_render
	do
		if render_done then return
		render_done = true
		rendering
		freeze
	end
lib/template/template.nit:189,2--200,4