Improve timeout in input plugins

plugins/inputs/apache/apache.go

plugins/inputs/couchdb/couchdb.go

plugins/inputs/disque/disque.go

plugins/inputs/dovecot/dovecot.go

plugins/inputs/elasticsearch/elasticsearch.go

plugins/inputs/haproxy/haproxy.go

plugins/inputs/httpjson/httpjson.go

plugins/inputs/influxdb/influxdb.go

plugins/inputs/jolokia/jolokia.go

plugins/inputs/mailchimp/chimp_api.go

plugins/inputs/mesos/mesos.go

plugins/inputs/mysql/mysql.go

plugins/inputs/mysql/mysql_test.go

plugins/inputs/nginx/nginx.go

plugins/inputs/nsq/nsq.go

plugins/inputs/prometheus/prometheus.go

plugins/inputs/rabbitmq/rabbitmq.go

plugins/inputs/raindrops/raindrops.go

plugins/inputs/redis/redis.go

plugins/inputs/riak/riak.go