#2240 dtm: Refactor the inter-node poll loop

[Anders Widell]

Re-factor the DTM inter-node poll loop with the aim to increase scalability and performance. Today the poll loop has a fixed-length array with 103 positions, with puts an upper bound on the size of the cluster of 100 nodes. This limitation should be removed and the loop should be optimized to cope with larger clusters.

[Anders Widell]

commit dea71bb783cc80d6dfb1fb6e761e86d9f7856d72 (HEAD -> develop, origin/develop)
Author: Anders Widell an..@..com
Date: Wed Aug 16 11:50:30 2017 +0200

dtm: Support clusters with more than one hundred nodes [#2240]

Re-factor the inter-node poll loop by replacing the 100 entry fixed size poll
vector with a epoll event processing. This allows dtm to scale to clusters
larger than 100 nodes.