Merge pull request argotorg#6269 from ethereum/develop

Merge develop into release for 0.5.6

Merge pull request argotorg#6188 from ethereum/develop

Release 0.5.5

Merge pull request argotorg#5975 from ethereum/develop

Release 0.5.4

Merge pull request argotorg#5836 from ethereum/develop

Merge develop into release for 0.5.3.

Merge pull request argotorg#5697 from ethereum/develop

Merge develop into release for 0.5.2

Merge pull request argotorg#5571 from ethereum/develop

Version 0.5.1

Merge pull request argotorg#5416 from ethereum/develop

Merge develop into release for 0.5.0

Merge pull request argotorg#4957 from ethereum/develop_v0425

Merge to release for 0.4.25

Merge pull request argotorg#4148 from ethereum/develop

Merge develop into release for 0.4.24

Merge pull request argotorg#3950 from ethereum/develop

Merge develop into release for 0.4.23