Add tabs and the ability to show them side by side.

[ApostolosB]

Feature request. As the title suggests. Making it possible to have 2-3 documents open side by side makes it easier to compare/copy/edit/whatever.

Also some kind of diff option between the open docs could come handy.

[wltjr]

I do plan to add tabs at some point. Not sure about the diff aspect. It maybe possible. EDI does show diff side by side. Not sure if that is part of elm code or EDI features. Either way maybe something possible down the road but will be a ways. I think I added tabs into the todo for down the road, stage 2 or something. A slew of other bugs and core features I want to see implemented first. Lack of tabs has bothered me with kwrite for sometime. Also something needed for mobile I believe.

It will require some major changes because the document is opened/used in a global scope. It was coded that way originally. I have to change that and it will break allot of stuff and may require changing some function. Probably do that once other issues are addressed. I do not want to convolute the issues.

[wltjr]

Slowly working towards tabs. I think I am close having removed most all global variables that hindered such. Not sure about the comparing side by side, but tabs will be coming. No ETA.

[wltjr]

I think one of the last obstacles will be in how I do the actual tabs. It does not seem like Elementary has any tab containers or widgets. For epad it used modifications in python-elm-extensions, one of which is tabbed box... :) Pretty sure that is what epad uses for its tabs. I have to look into how edi does tabs.