Gst::Query: wrapped missing methods from Query class

    * gstreamer/src/gst_extra_objects.defs: added definition of GstQuery
      object.
    * gstreamer/src/pad.hg: removed unnecesary #include directive, what
      leads to a circular dependency.
    * gstreamer/src/query.ccg:
    * gstreamer/src/query.hg: created missing query types: QueryCaps,
      QueryScheduling, QueryAllocation, QueryUri, QueryAcceptCaps.
      Implemented a few methods from already implemented classes.
      tests/test-query.cc: added simple test, which helps me to check
      references.
    * tools/m4/convert_gst.m4: conversion definitions of enums from query
      file, Structure class.
Gst::MiniObject: added a wrappers for the rest of nonexisting methods.

    * gstreamer/src/gst_extra_objects.defs: added extra class definition.
      for GstMiniObject struct.
    * gstreamer/src/miniobject.ccg:
    * gstreamer/src/miniobject.hg: added missing wrappers, also added
      QuarkData class, which should be used as a base class for data
      stored as a qdata.
    * tests/test-miniobject.cc: a few tests added, which check finalize
      notifier.