Also update BUILD.txt

This is heavy noise and low-usefulness for debugging normal
operating issues.

We have converted to using dhash in place of btreemap everywhere
in the code.

This reverts commit 8c50bd085c0efe5fde354deee2c8118887aae29d.

Amended: commit 1016af2b1b97ad4290ccce8fa462cc7e3c191b2e also made
use of the SYSLOG_ERROR() macro, so those portions of that code
also needed to be reverted.

This is just a band-aid until ELAPI is fully functional and ready to
use.

Fixes: #138

It seems like DBUS always adds 2 watches for the same fd.
One is for reading and the other is for writing.
DBUS then keeps disabling one and enabling the other, depending on whether
it is interested in reading or writing from/to the file descriptor.

Let services identify themselves voiluntarily as the first operation
instead of polling from the monitor.
Also consolidate some common functions and make them available as monitor
helpers.

Make as much as possible static, and remove use of talloc_reference and
allocation/deallocation of memory when not necessary.
Fix also responder use of rctx->conn, was mistakenly used for both
monitor and dp connections.