Fix Bono/Sprout handling of failed SAS connection
Add 30 second timeout to SAS connection
Firewall against failing to open a log file
Improve logging of HTTP connection errors
Discard incoming non-OPTIONS requests if queue is too large
Add latency statistics for HSS and XDM
Improve logging and retry behaviour on Homestead (and Homer) lookup failures
Remove rough overload control code (moved to an experimental branch
Fix valgrind issues - significant leak on registration errors and one uninitialised variable
Merge pull request #201 from Metaswitch/valgrind_issues

[Reviewer Matt] Fix valgrind issues - significant leak on registration errors and one uninitialized variable
Don't enable ENUM lookups by default
Merge pull request #202 from Metaswitch/issue178

[Reviewer Andy] Issue178
Fix leaking of flows.
Add missing src_flow decrement.
Factor out determine_source function.
Make interface to determine_source more general, so that it can be used without an rdata.
Add DialogTracker class.
Handle (un)quiesce signals and pass notifications to the stack module
Fix compilation errors
Fix up UT failure.