Issue 5433 - add option to use prebuilt v8

#depends on https://codereview.adblockplus.org/29493562/

[sergei, 2017-07-20 12:09:05]

https://codereview.adblockplus.org/29493566/diff/29493578/v8.gypi
File v8.gypi (right):

https://codereview.adblockplus.org/29493566/diff/29493578/v8.gypi#newcode33
v8.gypi:33: '<(libv8_lib_dir)/libv8_libplatform.a',
For android it's required to specify .a files, one cannot simply use
-lsome_thing.

[hub, 2017-07-20 12:55:35]

LGTM

[sergei, 2017-07-20 13:23:22]

Forgot to add how to use it, commit message has been updated.

[hub, 2017-07-20 13:43:10]

On 2017/07/20 13:23:22, sergei wrote:
> Forgot to add how to use it, commit message has been updated.

where should we document this then? I think in the README it should be fine.
Mark it as unsupported.

[sergei, 2017-07-20 13:54:47]

On 2017/07/20 13:43:10, hub wrote:
> On 2017/07/20 13:23:22, sergei wrote:
> > Forgot to add how to use it, commit message has been updated.
> 
> where should we document this then? I think in the README it should be fine.
> Mark it as unsupported.

I would just leave it in the commit message, your opinion?

[hub, 2017-07-20 16:12:34]

On 2017/07/20 13:54:47, sergei wrote:
> On 2017/07/20 13:43:10, hub wrote:
> > On 2017/07/20 13:23:22, sergei wrote:
> > > Forgot to add how to use it, commit message has been updated.
> > 
> > where should we document this then? I think in the README it should be fine.
> > Mark it as unsupported.
> 
> I would just leave it in the commit message, your opinion?

That's my point. The commit message isn't the right place for that. :-/

[sergei, 2017-07-20 20:00:28]

On 2017/07/20 16:12:34, hub wrote:
> On 2017/07/20 13:54:47, sergei wrote:
> > On 2017/07/20 13:43:10, hub wrote:
> > > On 2017/07/20 13:23:22, sergei wrote:
> > > > Forgot to add how to use it, commit message has been updated.
> > > 
> > > where should we document this then? I think in the README it should be
fine.
> > > Mark it as unsupported.
> > 
> > I would just leave it in the commit message, your opinion?
> 
> That's my point. The commit message isn't the right place for that. :-/

This description has been moved into readme file.

[hub, 2017-07-20 20:01:30]

Excellent !

LGTM