Update write_http.c

Adding abort on stuck connection
Conflicts:
	src/write_http.c
Update write_http.c - adding Low Speed Limit

Adding possibility to configure curl connection abort on slow connections. Reconnect on stuck or really slow connection sounds better than been stuck.
Conflicts:
	src/write_http.c
write_http.c - Indentation fix

Indentation fix
Conflicts:
	src/write_http.c
write_http.c - removed duplicate line
Update collectd.conf.pod - adding LowLimit params

Adding LowSpeedLimit and LowLimitBytesPerSec to spec
Conflicts:
	src/collectd.conf.pod
Update write_http.c - indentation again
Conflicts:
	src/write_http.c
Update write_http.c - adding Post timeout

Adding PostTimeoutSec to set max timeout on http post
Update collectd.conf.pod - adding PostTimeout parameter description
Merge pull request #5 from Stackdriver/write_http_fix

Cherry-pick LowSpeedLimit parameters from Loginator.