#20 SFTP Offset Retrieval and Target File Appending

[acarlton]

Implemented ability to retrieve using an offset which is
the offset (in bytes) relative to the beginning of the file
from where to start reading.

Also, included is the ability to append to a differently
named target file.

The following is a code snippet from a test program
which retrieves using an offset and appends to an
existing file.

int i = rand.nextInt(10001);
System.out.println("random int: " + i);
sftp.get("test2.txt", "partial.txt", (i-1)*6, true);

[acarlton]

2 Files for implementation of Offset Retrieval and File Appending