port to ModemManagerQt and split the gui and daemons to subprojects

Introducing new related subprojects:

• kde-telephony-plugin-declarative — org.kde.telephony QML plugin to work with the daemon
• kde-telephony-daemon — telephony daemon with org.kde.telephony D-Bus interfaces (KDE-specific: contacts, audio, notifications), depends on calls-daemon
• modem-daemon — general daemon with org.kde.telephony D-Bus interfaces (not KDE-specific: ModemManagerQt, calls history and dialing, dtmf, ussd); similar to mmsd and vvmd
• kde-telephony-meta — D-Bus XML Interface descriptions and Qt meta types to simplify complex types re-usage among the QML plugin and the daemon

Rename QML interface from org.kde.plasma.dialer to org.kde.telephony.

Contributes to #10 (closed) and #39 (closed)