Check_MK Werk 8568: Make sending data to Carbon/Graphite more robust.

ID: 8568 Title: Make sending data to Carbon/Graphite more robust. Component: cmc Level: 1 Class: Bug fix Version: 1.4.0i1 When the connection to Carbon/Graphite is slow and/or the kernel on the monitoring server is very busy, it could happen that we sent a partial line only, so the net result could look like the core is stuttering. With this fix, we introduce a small timeout for each write before giving up, and we make sure to close the connection in that case. It will be re-opened later automatically.