[telepathy] Remove unique suffix on the Telepathy handler name

There is no point in registering as a unique handler unless there can be
multiple instances of the handler, and it makes the exact name
unpredictable.
[telepathy] Use normal ensure functions instead of ensureAndHandle for creating channels

The ensureAndHandle variants create and register a handler instance
internally, then create the channel request with that handler as the
preferred one. Since we already have our own handler published, that's a
lot of unnecessary and slow dbus traffic and potential for bugs.
[telepathy] Share the Tp::AccountManager instance with Tp::ClientRegistrar

This allows the accounts and connections created by ClientRegistrar to
be the same as those created via that AccountManager directly.
[telepathy] Remove useless and unused handlerAdapters map

QDBusAbstractAdaptor classes are freed automatically when the parent
object is.
[voicecall] Fix incoming ring tone.

Incoming call status is initially null using telepathy plugin. The status
shouldn't be updated when a call is added if the status is null.

Regression due to eb73012e9a54281ac4705367d5c36c7ad46f86b5
Merge pull request #34 from martinjones/master

[voicecall] Fix incoming ring tone.
Merge pull request #33 from special/telepathy-cleanup

[voicecall] Minor cleanup to TelepathyQt usage in the provider plugin
[voicecall] Update call duration more reliably.
Merge pull request #35 from martinjones/jb9079

[voicecall] Update call duration more reliably.
[lib] Remove useless Q_DECLARE_INTERFACE lines for non-plugin classes

These serve no purpose, and break the use of qobject_cast unless
Q_INTERFACES is used, which none of the subclasses do.
[ngf] Fix crash and fragility with handlers in NGF ringtone plugin

The currentCall variable would hold the most recently added handler, and
was cleared when that stopped ringing. In some cases, that could be null
or invalid when another handler's status changed, resulting in a crash.
[ngf] Fix casting -1 to unsigned for invalid event IDs

The event ID is quint32. An error or invalid event is ID 0, not
(unsigned)-1.
[ngf] Stop the ringtone instead of pausing when silenced

Since there is no way it can be resumed, there's no reason to pause
instead of stop the ringtone. Since the event ID was also cleared, the
event would actually never be stopped.
Merge pull request #36 from special/ngf-cleanup

Fix crashes and bugs in NGF ringtone plugin
[voicecall] Expose telepathy ChannelCallStateForwarded call state.
Merge pull request #37 from martinjones/forwarded

[voicecall] Expose telepathy ChannelCallStateForwarded call state.
Merge branch 'master' of https://github.com/nemomobile/voicecall into no-telepathy-ring

Signed-off-by: Tom Swindell <t.swindell@rubyx.co.uk>