Fix unzipping under Darwin: force overwriting of existing files.

Fixes http://teampulse.telerik.com/view#item/274387
Merge pull request #54 from telerik/totev/unzip

Fix unzipping under Darwin: force overwriting of existing files.
Fix Bug "[CLI] disconecting ios device when open-device-log-stream is active causes CLI to become unresponsive"
http://teampulse.telerik.com/view#item/262230