All boost async operations need to occur in the context of the same task i.e.
the task that is executing run(). In our case, its the main task.
io_service.post() guarantees that the handler will only be called in a thread
in which the run(), run_one(), poll() or poll_one() member functions is
currently being invoked. But, there are no guarantees wrt to ordering.
Using strand.post() guarantees the thread and also has some ordering
guarantees. In our case, we have the main-task and sm-task that are competing.
Intuitively, it makes sense to enforce ordering of callbacks since the events
triggering the callbacks are ordered and this is a state-machine where the same
event in a different state could cause issues. So, we will use strand.post().
Also, adding a small macro to check if we are running in the context of the
main-task and using it to check that we are in the right context while
executing the boost-async calls.
Commit to github to Handle 503 error due to Discovery Server not UP
Fix cut-paste error in definition of CHECK_CONCURRENCY_MAIN_THR
Merge pull request #243 from Juniper/tkarwa_script

All boost async operations need to occur in the context of the same task...
Merge pull request #245 from Juniper/ds_503

Commit to github to Handle 503 error due to Discovery Server not UP
changes for independent redis-uve instances
remove unused code
Merge pull request #247 from manishsing/master

remove unused code
Merge pull request #246 from Juniper/sundar_controller

changes for independent redis-uve instances
fix build break
Merge pull request #251 from manishsing/master

fix build break
1. Accept ARP replies even when agent has not sent ARP request. Add UT for same
2. Send target hw-address to zero's in all cases
3. Dont pad ARP packet to 64 bytes. Set size of ARP packet to 42 bytes
4. Fix crash in meta-data if we get response after TCP session close
Merge pull request #253 from praveenkv/master

1. Accept ARP replies even when agent has not sent ARP request. Add UT f...
Merge remote branch 'upstream/master'

Conflicts:
	src/vnsw/agent/services/metadata_proxy.cc