This patch introduces the notion of a "domain" to the nitpicker
configuration concept. Session policies always refer to a domain where
multiple session policies can refer to the same domain. Thereby a domain
provides a way to express the grouping of sessions. This is useful for
applications that open multiple nitpicker sessions (such as Qt5 apps that
use one nitpicker session per window, menu, etc.). We want to assign all
those sessions to a single domain.
The configuration looks as follows:
<config>
...
<domain name="default" color="#ffffff"/>
<policy label="" domain="default"/>
...
</config>
So far, the lifetime-management utilities 'Weak_ptr' and 'Locked_ptr'
had been preserved for core-internal use only. However, the utilities
are handy for many use cases outside of core where object lifetimes
must be managed. So we promote them to the public API.
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.
Issue #1082
