(cherry picked from commit 0c10d376)

(cherry picked from commit 19bfcbf9)

(cherry picked from commit 7c60d0a6)

(cherry picked from commit 1c3aa8d9)

(cherry picked from commit 4f3d22f0)

(cherry picked from commit 41597c28)

(cherry picked from commit d212535d)

(cherry picked from commit c5c9cef5)

(cherry picked from commit b91bf088)

(cherry picked from commit 7f55b0cb)

(cherry picked from commit 3eff652a)

(cherry picked from commit f9401ae0)

(cherry picked from commit 592bf6a5)

(cherry picked from commit 2abeb35d)

(cherry picked from commit ad13d2d4)

(cherry picked from commit fa34429a)

(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)