Proposal: default --tlsverify=true if talking to :2376

2376 is registered as the encrypted Docker API port - so defaulting to that would simplify the UI and the user documentation.

if someone can tell me how to resolve the TODO, and if the UX is acceptable, I'll go make it happen.... 

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)