Login and perform operations with HiveSigner.
For more details, please refer to https://peakd.com/hive-139531/@good-karma/imagehoster-hivesigner-and-condenser-bounty#@roomservice/re-good-karma-qd5qsb
The Merge Request contains almost the same change as condenser!74 (merged), except some minor differences.
Fixes: condenser#43 (closed)