Ask where to download the blockhain

[falinatecas]

This way users can select the drive and directory where the blockchain will be kept.

[Diapolo]

Just use the -datadir option.

[falinatecas]

Just to make the GUI more user friendly - although there are other clients out there for newbs, aiming to be user friendly, but bitcoin-qt is usually the first one that new bitcoiners meet, and it can cause frustrations not knowing that 9GB will be downloaded somewhere to the system partition. This might need to be emphasized.

[laanwj]

I guess it could ask if you want to customize the datadir at first run or after installation...

[laanwj]

I've started working on this.

When bitcoin-qt is started with a data directory that does not exist yet (ie, the first time), it will pop up an intro screen in which a data directory can be chosen.

[falinatecas]

That's great, thank you.
Do you plan to include a note about the approx size of the blockchain that needs to be downloaded to the selected dir?

[gmaxwell]

One thing to do might be to not permit selecting a location that doesn't have enough space free.

[laanwj]

@gmaxwell yes, that's the intention

[laanwj]

See #2670