Merge pull request ethereum#3537 from karalabe/release-1.5.6

params: stable version 1.5.6

Merge pull request ethereum#3440 from karalabe/release-1.5.5

params: stable version 1.5.5

params: stable version 1.5.4 (ethereum#3360)

cmd/utils: 1.5.3 stable

core: Don't perform EIP150 hash check on uncles (ethereum#3303)

Merge pull request ethereum#3278 from obscuren/version-1-5-1

utils: bump stable 1.5.1

Merge pull request ethereum#3259 from obscuren/version-1-5-0

utils: stable 1.5.0

Merge pull request ethereum#3252 from obscuren/release/1.4

1.4 HF

Merge pull request ethereum#3144 from ethereum/release/1.4

Release/1.4.18 to master

Merge pull request ethereum#3116 from fjl/release/1.4

Backport TxPool limits to release/1.4