Adding scan for virustotal module

I modified virustotal module and add a few options:
--scan - scan all samples from repository and output status (you can submit samples to VS)
--engine - additional option for scan. Output signature for chosen antivirus engine
--resubmit - reanalyse sample

Scan:
![scan_files](https://cloud.githubusercontent.com/assets/1186777/4412912/0b07d742-44fe-11e4-8a23-f8dd43b1bdba.png)

Scan with submit:
![submit](https://cloud.githubusercontent.com/assets/1186777/4412915/18299852-44fe-11e4-8c1e-0d8fc9840671.png)