CCBC-192 Skip misconfigured nodes in the list

Change-Id: If83edfe5e511187ec15aa7484aba075c7d3541ec
Reviewed-on: http://review.couchbase.org/28444
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Mark Nunberg <mnunberg@haskalah.org>
CCBC-244: [bconf_io] Don't be so liberal with maybe_breakout

Change-Id: I00d8ab6aa9d435aebcb9234665f70f2d16a2b8ab
Reviewed-on: http://review.couchbase.org/28341
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Mark Nunberg <mnunberg@haskalah.org>
CCBC-246 Fallback to 'select' if default plugin cannot be loaded

On UNIX-like systems, default IO backend is libevent, which is
third-party library and the plugin itself goes in separate package and
could be not available at the run-time

This patch allows to fallback to 'select' plugin only if the user will
pick default IO backend

Change-Id: I834b35f5614d10da75635899589192b073a2e91b
Reviewed-on: http://review.couchbase.org/28374
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Matt Ingenthron <matt@couchbase.com>
Reviewed-by: Mark Nunberg <mnunberg@haskalah.org>
Simplify Travis-CI build: check only select

Change-Id: If42b051e5c9109ba75abfa5a9236c32b677f3ddb
Reviewed-on: http://review.couchbase.org/28448
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
[travis] forgot to disable plugins

Change-Id: I013165864a00f26627ff02409df8be232bd7fe8e
Reviewed-on: http://review.couchbase.org/28451
Reviewed-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>