Questions regarding switchin' from 6.13.12 to 6.15

[Levrex]

1) On Ren'Py 6.13 the sound that is playing will be interrupted when you call another screen (like game menu or text history) or do something like that. Looping sounds (like music), on the other hand, are not interrupted. It was fixed either in 6.14 or in 6.15.
Since the game has fairly long sounds, i would like to somehow port the code that was added somewhere later, which enables the sounds to continue playing even if you open a game menu. I took a look at the code in 6.15 renpy folder, but couldn't find anything, and so i'm asking — what code do i need to port the «non-interrupting sounds thing» from 6.15 to 6.13?

2) Well, actually, if i simply take "renpy" and "lib" folders from Ren'Py 6.15 directory and simply replace the old 6.13 folders, and change the "script version" to 6.15 (or won't), would the game work as it was on 6.13? Because 6.15 has quite a lotta neat changes (like console, screen parameters and etc) and it would be nice to make use of them too.

Out of possible non-standard means, i use the math module, most of the ATL functionality that is available in 6.13.12 and text history screen by apricotorange.

3) And then, if i move the "common" folder from "renpy" folder back to where it was in 6.13 (core folder of the game, the one where the executable is), would i experience any undesired effects? Will it work or do i need to change something?

[SundownKid]

If you update your Ren'py version in the launcher, the game should follow suit and automatically update. There's no need to modify it manually, just updating or dropping the game folder in the new version's folder will do the trick.

[Levrex]

No, i'm afraid it doesn't.

To clarify if there's a misunderstanding, the game is a huge one and located in a separate folder from the launcher. It has its own "renpy", "lib" and "common" folders, since i was working with the ready-for-distribution build from long ago.

(And is usually launched from its own executable, not from renpy launcher.)

[SundownKid]

Are you sure you're working with the unpacked game file, or the one that has been built? Anyway, what about if you simply put the "game" folder into a new folder and added it to the new launcher? Those other ones shouldn't be necessary.

[Levrex]

I'm working with the built distribution, i'm certainly sure of that.

Anyway, what about if you simply put the "game" folder into a new folder and added it to the new launcher? Those other ones shouldn't be necessary.

While that is, of course, totally true, it still doesn't answer my questions.
In part because of habit, in part because of the need for the game to be stand-alone from renpy, in part because the game has many manually modified files in common and renpy folders.

[AxemRed]

... because the game has many manually modified files in common and renpy folders.

You're royally boned.

[Levrex]

Maybe; however, as far as i had the patience to look through, the most changes in the files i modified are copyright terms (2012 -> 2013) and nothing more.

===

Nevertheless, if i better won't even bother switching from 6.13 to 6.15, what would be the code that fixes the non-looped files interrupting issue, or which keywords would help me find it?