Generate asynchronous getters for DBus properties
Generate asynchronous getters for DBus properties

The new getters are named requestPropertyFoo, where Foo is the property
name, and return a Tp::PendingVariant. They will replace completely the
synchronous getters after the API break.

freedesktop-unofficial-mirror/telepathy__telepathy-qt4,detrout/telepathy-qt,TelepathyQt/telepathy-qt,detrout/telepathy-qt,TelepathyQt/telepathy-qt,TelepathyIM/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,special/telepathy-qt-upstream,TelepathyIM/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,anantkamath/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,special/telepathy-qt-upstream,special/telepathy-qt-upstream,TelepathyIM/telepathy-qt,TelepathyQt/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,TelepathyQt/telepathy-qt,TelepathyIM/telepathy-qt,tiagosh/telepathy-qt,TelepathyIM/telepathy-qt,tiagosh/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,anantkamath/telepathy-qt,tiagosh/telepathy-qt,detrout/telepathy-qt,anantkamath/telepathy-qt,tiagosh/telepathy-qt