helpers: add --quiet argument for non-interactive MW building

[JamiKettunen]

Without this one had to do something like echo a | build_packages.sh --mw, but we might as well include a flag that does the same thing.

[Thaodan]

I don't think this is a good change since when you pass --quiet it still talks too you. I think the script shouldn't ask in the first place if you want to build all. There are two choices that make sense imho, either: 1. Make so that --mw with no package passed assumes to build all packages. 2. Ask to explicitly to pass --mw=all if the user wants to build all and fail of if all or package name wasn't passed.

[JamiKettunen]

@Thaodan why not a third option: keep current behavior of the script but add the tweaks of this PR behind --mw=all? I can see how the interactive option is useful as well for some people due to MW package builds breaking somewhat often, so then that package can be reset back to a known working version, run --mw and choose no for most except all when the previously broken package shows up again, then the script continues to build the remaining MW in order.

[sledges]

Here's 4th option: add -y, --non-interactive global switch and latch from MW side (later other parts can also take use easily), also the short cmdline gets simpler: -ym instead of -m all

[Thaodan]

That would work, I think the default should be what is used most.
Building all or just building some?
I think building all in that case asking if I really want to do that is annoying.