backport preferred master changes from 1.7 + required dependencies
(GET_TXID, NOP, Client_main.with_connection')
Merge branch 'incubaid-1.6' into backport-preferred-master

Conflicts:
	src/node/node_main.ml
Merge pull request #486 from Incubaid/backport-preferred-master

backport preferred master changes from 1.7 + required dependencies