Organize the epiphany base design and add libraries to the repository.

	* epiphany-base/epiphany-base.scad: Simplified based on including files.
	* epiphany-base/epiphany-base.stl: Regenerated.
	* epiphany-base/epiphany-core.scad: Moved the module definitions
	to this file for inclusions.
	* epiphany-base/epiphany-dimensions.scad: Moved the dimensioning
	code to this file.
	* epiphany-base/epiphany-parameters.scad: Moved the parameters
	defining the base to this file.
	* epiphany-base/epiphany-spacer.scad: A separate module for the
	spacer component.
	* epiphany-base/epiphany-spacer.stl: Generated from the SCAD file.
	* libraries/TextGenerator.scad: Created from upstream file.
	* libraries/dimlines.scad: Likewise.