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
geoip: fail gracefully if geoip-lite isn't installed
data.headers: fail gracefull if address-rfc2822 not installed
graph: handle 'sqlite3' not installed gracefully
net_utils: s/stun/vs-stun/

vs-stun:
  works with current versions of node.js
  has a nicer API
  provides more net topology data (we don't need it, but nice to have)
package.json: s/stun/vs-stun/, added redis as optional dep
port465: added port 465 TLS listener

added port 465 to "require AUTH"
server: consoldiated duplicate callback
Merge branch 'port465' into toaster
Merge branch 'net_utils' into toaster
Merge branch 'headers' into toaster
Merge branch 'graph' into toaster
Merge branch 'geoip' into toaster