Seperate OPC and 5-step checkouts

[markahesketh]

.tpl files for the order process are very confusing in default theme.

Contain a lot of code and conditionals for OPC/5-step checkout.

Seperate this code out into dedicated files.

[alexsegura]

Totally agree.

Tired of seeing all these {if $opc} / if {!$opc} everywhere.

What about deprecating non-OPC method ?

[markahesketh]

I think both the 5-step and OPC need to be there.

My plan was to have every feature from the back office compatible with the theme, as I intend to use it not just for client projects but also potentially premium themes if I ever find the time!

It definitely needs cleaning up though, its a mess!