Add progress indicator

[Sergey Podobry]

As download/upload can be a long running operation the log will show the current progress:

Downloading 1715 files from sftp://192.168.2.139/home/sergius/CCC
Progress: 12% (214 from 1715)
Progress: 24% (428 from 1715)
Progress: 37% (642 from 1715)
Progress: 49% (856 from 1715)
Progress: 62% (1070 from 1715)
Progress: 74% (1284 from 1715)
Progress: 87% (1498 from 1715)
Progress: 99% (1712 from 1715)

[Sergey Podobry]

Fixed in 1.0.2.