Release 1.8.1

This is mostly a bug fix update:

• Fix the new Force index file re-read every ... option in the Advanced settings tab, which was not working. (@gyunaev)
• The uninstaller that is bundled in the Windows release for 1.8.0 will always remove all Birdtray settings, regardless of the checkbox. Because this also affects updating, Windows users who have installed 1.8.0 must install this update before they update to any other future Birdtray version. Otherwise you will loose your settings. (@Abestanis)

Additions:

• Add Russian translations. (By @KOV70)
• Add Portuguese translations. (By @igorruckert)
• Add Spanish translations. (By @rplanchuelo)
• Add support for finding ExQuilla Exchange accounts. (@Abestanis)

Changes:

• The Windows installer no longer chooses and remembers a default language if run in silent mode. (@Abestanis)