Avoid a ThreadKilled timeout in the polling thread

The polling thread now has its own timeout. If we are unable to produce
any data in 45 seconds, we simply emit a ping. Not necessarily the most
sensible response, but we don't deal with timeouts anyway at the moment,
so this is sufficient to keep the connection alive (by both parties).
Disable websockets
Merge branch 'master' into control-for-polling-timeout

Conflicts:
	engine-io/src/Network/EngineIO.hs
engine-io: Add dupRawReader
socket-io: Add ReaderT Socket to building routing tables
socket-io: Add `engineIOSocket` to retrieve the underlying socket
Revert "Disable websockets"

This reverts commit 148e1f7273242d0abe137d40a12500bb8988e207.
Increase upper version bounds

The new bounds include the text-1.2, conduit-1.2 and websockets-0.9
releases.  I've tested the chat and latency examples with these
package versions, and both still work.
Compile examples with -threaded.

This fixes the error `registerDelay: requires -threaded`.
Rename latency example executable to 'latency-example'.

'latency' is also a MacOSX/BSD system utility.
Include all needed resources in the latency example with 'Data-files'.