Splitcopy

Features Added:
* None
Bugs Fixed
* With the arrival of OpenSSH v7.4, an additional process is created under the user's id when using SCP to transfer files. Some transfers would fail due to hitting the max processes per uid. Amended the logic that determines the number of file chunks created as a result.

Features Added:
* Improved scp exception handling
* Remote tmp dir name is now unique which eliminates re-use problems.
* Silenced 'retrying file' logs once retry limit has been hit by one file
Bugs Fixed:
* None

Features Added:
* None

Bug Fixes:
* updated remote_check() to correctly parse 'df' output when length of volume string causes line wrapping.

Features Added:
- removed restriction that remote host must be Linux/FreeBSD based
- added support for 'shasum' on remote host for sha1 generation

Bugs Fixed:
- remote sha1 generation would fail for '--get' operations if binary used was sha1sum