Remove region/host defaults, add apimode tanks/planes, setRegion changes

Incompatible changes:

Default Region and host removed.

In __construct: baseHost renamed to host. $host will always contain the full hostname now.

When calling setRegion then customHost bool will be set to false.

setApiMode now required for api to function.

Hostname required via either: setRegion or setHost

Official wargaming hostnames are generated in the setRegion function.

```
$client->setApiMode(Client::TANKS);

$client->setRegion(Client::REGION_RUSSIA);
$client->setHost('example.ru')
```