Better Nornir Config file support; drier dry runs; netconf edit config diffs

• actually support nornir config file ssh config file option
• improved dry run handling (and support of global dry run) for send config(s) methods
• added dry run handling for netconf edit config
• added diff capability for netconf edit config
• diff coloring -- red for remove, green for addition (again, only netconf)
• dev pin updates