PCT-743: Update gocheck
Fix agent-build
Remove some excessive debug statements.
Clean up debug statements.
Merge branch 'agent-tweaks' of github.com:percona/percona-agent into agent-tweaks

Conflicts:
	client/ws.go
Merge pull request #77 from percona/agent-tweaks

Remove some excessive debug statements
Merge pull request #72 from percona/PCT-743_update_gocheck

PCT-743: Update gocheck
Merge branch 'release' into PCT-748--runtime-error-on-nil-conn

Conflicts:
	mysql/mysql_test.go