Merge 0.11->trunk

MUC: Fix delay tag @from in test to be the room JID (#1054 came back)

MUC: Fix delay@from to be room JID (fixes #1416)

MUC: Add a test covering basic room creation, messages and destruction

net.server_epoll: Add support for opportunistic writes This tries to flush data to the underlying sockets when receiving writes. This should lead to fewer timer objects being around. On the other hand, this leads to more and smaller writes which may translate to more TCP/IP packets being sent, depending on how the kernel handles this. This trades throughput for lower latency.

core.certmanager: Remove unused import [luacheck]

Remove COMPAT with temporary luasec fork The changes in the temporary fork were merged into mainline luasec ca 2013 and included in the 0.5 release in 2014.

MUC: Simplify nickname refresh loop Affiliation data is passed as a loop variable so no need to retrieve it

core.certmanager: Move EECDH ciphers before EDH in default cipherstring The original intent of having kEDH before kEECDH was that if a `dhparam` file was specified, this would be interpreted as a preference by the admin for old and well-tested Diffie-Hellman key agreement over newer elliptic curve ones. Otherwise the faster elliptic curve ciphersuites would be preferred. This didn't really work as intended since this affects the ClientHello on outgoing s2s connections, leading to some servers using poorly configured kEDH. With Debian shipping OpenSSL settings that enforce a higher security level, this caused interoperability problems with servers that use DH params smaller than 2048 bits. E.g. jabber.org at the time of this writing has 1024 bit DH params. MattJ says > Curves have won, and OpenSSL is less weird about them now

mod_storage_internal: Include last text message A protocol built on this API now allows showing a list of unread conversations with a counter, ordered by either oldest or newest message, along with the text body itself.