connection: check for transaction before attempts to access objects in it

so Haraka doesn't crash
Merge pull request #549 from msimerson/connection

connection: check for transaction before attempts to access objects in i...
smtp_proxy: bug fix, defines an undefined variable
Merge pull request #550 from msimerson/smtpproxy

smtp_proxy: bug fix, defines an undefined variable
Prevent duplicate newlines in bounce message
Fix example and prevent leak FDs
Increase the default open file limit in Upstart script
Fix date format on bounce messages
Fix timeout when processing mail
Merge branch 'master' of github.com:baudehlo/Haraka
weirdly related enhancements

* move is_ipv4_literal from plugins/helo.checks to net_utils
	so it's available for the SPF plugin

* SPF: skip HELO tests for IP literals

* SPF: when a connection has relaying permissions, use our (Haraka's) public IP in the SPF mail_from query, to determine if Haraka has permisison to send on behalf of that MAIL FROM domain.

* move the public_ip setting out of config/connect.geoip.ini to config/smtp.ini, used by GeoIP and SPF plugins.

* updated connect.geoip to use boolean config options
remove geoip config changes
spf: added [relay]context setting, and defer/deny settings for

helo/mfrom when relaying is set
spf: updated tests, added a couple more
removed spf from TODO rename list