Smoke tests

    cd test
    cat README.md
    ./setup.sh
    ./run_all.sh
Merge PR #241 from 'squaremo/smoke_tests'
Rename docs/testing.txt to avoid confusion now we have smoke tests
Explain multiple containers with same name

Two further scenarios described
Add `-tags net
explain crypto
and encapsulation
Move call to Topology.RebuildRoutes

It doesn't belong in handleBroadcastTCP(), so moved it up
to the two places that cause that function to be called.
Merge pull request #271 from bboreham/258_rebuild_routes

Move call to Topology.RebuildRoutes

Closes #258
refactor
simplify encapsulation diagrams
by dropping the standard packet headers
move explanation of peers and peer names
...plus some related doc shuffling
cosmetic
oops
grrr
Merge branch 'master' into 40_crypto_docs

Conflicts:
	site/how-it-works.md
some rewording and some links
fix typo
make it clear that key pairs are created per connection
cosmetic
state that nonce prepending is normal in NaCl