How can I set edges to a specific length with the keyboard? For a long time I've been trying to find a way to set selected edges to a specific length.

Since I can only find old posts from years ago and "only measure tools", I need to ask this: Is there a way to set an edge/or multiple selected edges to a fixed length inserted via keyboard? I use version 2.78 and it would help me a great deal, because I can't get past the basic setup for my objects without this. 

Of course, edges and faces can be drawn to a certain length and it will get shown by "Mesh Display", but the numbers are never accurate, so now I want to set those edges to have a very specific length. How do I do this, because I can't find any useful videos or posts that would show this?
No, you just cannot set the edge length by typing a number. I don't know why Blender does not add this feature, it's just stupid. 

--Edit--

Just found an Add-on
https://developer.blender.org/T39999  After putting the .py file into your addons folder you can just use Shift-Alt-E to set the edge length