Valetudo 0.4.0-RE2 preview

Sixth release for testing RE version, verified on S55 (fw 1886).

The only new feature is possibility to export and import Forbidden Zones and Virtual Walls settings to and from Valetudo configuration file. Other than that this release contains few small improvements and bugfixes.

Also some changes are related to pre-built binary:

• Node.js is updated to 10.16.1;
• Now it is built without intl support and some other features that seem to be useless for vacuuming, thus new binary size is smaller than usual.

I also remind that those who build firmware themselves using default packages still need to install into their device newer libstdc++ library, as described in deployment section. For those who download pre-built binary this step is not required.