(cherry picked from commit bbd12035)

(cherry picked from commit a0b0db63)

(cherry picked from commit 85a79b3a)

(cherry picked from commit 56095779)

(cherry picked from commit 632135ce)

(cherry picked from commit 257bfff3)

(cherry picked from commit 81e26d5a)

* swarm/network: fix skipped tests related to suggestPeer

* swarm/network: rename depth to radius

* swarm/network: uncomment assertHealth and improve comments

* swarm/network: remove commented code

* swarm/network: kademlia suggestPeer algo correction

* swarm/network: kademlia suggest peer

 * simplify suggest Peer code
 * improve peer suggestion algo
 * add comments
 * kademlia testing improvements
   * assertHealth -> checkHealth (test helper)
   * testSuggestPeer -> checkSuggestPeer (test helper)
   * remove testSuggestPeerBug and TestKademliaCase

* swarm/network: kademlia suggestPeer cleanup, improved comments

* swarm/network: minor comment, discovery test default arg

(cherry picked from commit bcb25941)

* cmd/swarm/swarm-snapshot: add binary to create network snapshots

* cmd/swarm/swarm-snapshot: refactor and extend tests

* p2p/simulations: remove unused triggerChecks func and fix linter

* internal/cmdtest: raise the timeout for killing TestCmd

* cmd/swarm/swarm-snapshot: add more comments and other minor adjustments

* cmd/swarm/swarm-snapshot: remove redundant check in createSnapshot

* cmd/swarm/swarm-snapshot: change comment wording

* p2p/simulations: revert Simulation.Run from master

https://github.com/ethersphere/go-ethereum/pull/1077/files#r247078904

* cmd/swarm/swarm-snapshot: address pr comments

* swarm/network/simulations/discovery: removed snapshot write to file

* cmd/swarm/swarm-snapshot, swarm/network/simulations: removed redundant connection event check, fixed lint error

(cherry picked from commit 34f11e75)

(cherry picked from commit 96c7c18b)

fixes: ethersphere/go-ethereum#1117
(cherry picked from commit f728837e)

(cherry picked from commit c0b9c763)

(cherry picked from commit 75a93147)

(cherry picked from commit 37e5a908)

(cherry picked from commit 9d3ea8df)

(cherry picked from commit dcc045f0)

(cherry picked from commit ba90a4aa)

(cherry picked from commit a8ddf7ad)

(cherry picked from commit edf976ee)

* common/fdlimit: cap on MacOS file limits, fixes #18994

* common/fdlimit: fix Maximum-check to respect OPEN_MAX

* common/fdlimit: return error if OPEN_MAX is exceeded in Raise()

* common/fdlimit: goimports

* common/fdlimit: check value after setting fdlimit

* common/fdlimit: make comment a bit more descriptive

* cmd/utils: make fdlimit happy path a bit cleaner

(cherry picked from commit f48da43b)

* build: use sftp for launchpad uploads

* .travis.yml: configure sftp export

* build: update CI docs

(cherry picked from commit 3de19c8b)

(cherry picked from commit b0ed083e)

This change clears up confusion around the two ways in which nodes
can be added to the table.

When a neighbors packet is received as a reply to findnode, the nodes
contained in the reply are added as 'seen' entries if sufficient space
is available.

When a ping is received and the endpoint verification has taken place,
the remote node is added as a 'verified' entry or moved to the front of
the bucket if present. This also updates the node's IP address and port
if they have changed.

This change resolves multiple issues around handling of endpoint proofs.
The proof is now done separately for each IP and completing the proof
requires a matching ping hash.

Also remove waitping because it's equivalent to sleep. waitping was
slightly more efficient, but that may cause issues with findnode if
packets are reordered and the remote end sees findnode before pong.

Logging of received packets was hitherto done after handling the packet,
which meant that sent replies were logged before the packet that
generated them. This change splits up packet handling into 'preverify'
and 'handle'. The error from 'preverify' is logged, but 'handle' happens
after the message is logged. This fixes the order. Packet logs now
contain the node ID.

dput --passive should make repo pushes from Travis work again.
dput --no-upload-log works around an issue I had while uploading locally.

debuild -d says that debuild shouldn't check for build dependencies when
creating the source package. This option is needed to make builds work
in environments where the installed Go version doesn't match the
declared dependency in the source package.

This PR adds a new fork which disables EIP-1283. Internally it's called Petersburg,
but the genesis/config field is ConstantinopleFix.

The block numbers are:

    7280000 for Constantinople on Mainnet
    7280000 for ConstantinopleFix on Mainnet
    4939394 for ConstantinopleFix on Ropsten
    9999999 for ConstantinopleFix on Rinkeby (real number decided later)

This PR also defaults to using the same ConstantinopleFix number as whatever
Constantinople is set to. That is, it will default to mainnet behaviour if ConstantinopleFix
is not set.This means that for private networks which have already transitioned
to Constantinople, this PR will break the network unless ConstantinopleFix is
explicitly set!

params: postpone Constantinople due to net SSTORE reentrancy