spamassassin: fixed Haraka crash when spamd_response.headers not defined

happens when local SA config doesn't enable that header and results in this:

[CRIT] [-] [core] ReferenceError: Invalid left-hand side in assignment
    at Socket.<anonymous> (/usr/local/haraka/plugins/spamassassin.js:88:13)
Merge pull request #583 from msimerson/spamassassin

spamassassin: fixes Haraka crash when spamd_response.headers not defined
update test to use 4.2.2.2 as 'test' hostname/ip
Merge pull request #589 from msimerson/testfix

update test to use 4.2.2.2 as 'test' hostname/ip
Added simple cmd line "haraka_grep".

Useful for finding log lines related to a particular string
Merge branch 'master' of github.com:baudehlo/Haraka
auth: limit delay to plugin.timeout

(so Haraka doesn't crash when the delay is set > plugin.timeout
s/this|self/plugin/ for consistency
added utils.valid_regexes
Merge pull request #591 from msimerson/auth-timeout

auth: limit delay to plugin.timeout
Support timestamping logs (finally)
Merge branch 'master' of github.com:baudehlo/Haraka
Merge pull request #592 from msimerson/utils2

added utils.valid_regexes
vpopmail: fail faster during a CRAM-MD5 auth attempt with an invalid username