v2.6.13

This release brings NTLM proxy support to the linux version of the RSSH client and enables the rssh client to correctly forward ipv6 addresses.

Features:

• Add cross-platform NTLM proxy authentication support by @nollium in #186
• link now supports --ntlm-proxy-creds argument to supply ntlm credentials e.g 'DOMAIN\USER:PASS'
• The rssh client now supports --ntlm-proxy-creds argument with same format for credentials.

Bug Fixes:

• The RSSH client now supports forwarding to ipv6 addresses correctly (was broken due to some incorrect concatenation
• Server now prints out ipv6+port correctly