Merge pull request #60 from garbetjie/master

Added limiting of max client connections.
Do not create a server instance with invalid socket
Bumped version to 0.3.17
Merge branch 'master' of github.com:andris9/simplesmtp
Bumped version to 0.3.18
Allow SIZE with MAIL
Whitespace fix
Implemented "NOOP" command
Allow responding dataReady events with custom error message
Merge pull request #64 from codingphil/implement_missing_commands

Implemented "NOOP" command
Merge branch 'master' of github.com:andris9/simplesmtp
Prefer setImmediate over nextTick if available
Bumped version to 0.3.19
Re-emit 'drain' from tcp socket
Bumped version to 0.3.20
Ignore OAuth errors from destroyed connections

Fixes #68
Merge pull request #70 from SLaks/patch-1

Ignore OAuth errors from destroyed connections
Bumped version to 0.3.21