libobs/util: Replace libdbus by GDBus

GDBus is more and better maintained than libdbus these days. In the
future, a potential Wayland-compatible capture plugin will need to
interact with D-Bus in a way that's way too complicated for libdbus,
and it won't be nice to have both libraries talking to the D-Bus
socket.

Replace the libdbus usage by GDBus. As it turns out, it results in less
code.

cmake/Modules/FindDBus.cmake

@@ -1,43 +0,0 @@
-# Once done these will be defined:
-#
-#  DBUS_FOUND
-#  DBUS_INCLUDE_DIRS
-#  DBUS_LIBRARIES
-
-find_package(PkgConfig QUIET)
-if (PKG_CONFIG_FOUND)
-	pkg_check_modules(_DBUS QUIET dbus-1)
-endif()
-
-find_path(DBUS_INCLUDE_DIR
-	NAMES dbus/dbus.h
-	HINTS
-		${_DBUS_INCLUDE_DIRS}
-	PATHS
-		/usr/include /usr/local/include /opt/local/include)
-
-find_path(DBUS_ARCH_INCLUDE_DIR
-	NAMES dbus/dbus-arch-deps.h
-	HINTS
-		${_DBUS_INCLUDE_DIRS}
-	PATHS
-		/usr/include /usr/local/include /opt/local/include)
-
-find_library(DBUS_LIB
-	NAMES dbus-1
-	HINTS
-		${_DBUS_LIBRARY_DIRS}
-	PATHS
-		/usr/lib /usr/local/lib /opt/local/lib)
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(DBus DEFAULT_MSG DBUS_LIB DBUS_INCLUDE_DIR DBUS_ARCH_INCLUDE_DIR)
-mark_as_advanced(DBUS_INCLUDE_DIR DBUS_ARCH_INCLUDE_DIR DBUS_LIB)
-
-if(DBUS_FOUND)
-	set(DBUS_INCLUDE_DIRS ${DBUS_INCLUDE_DIR} ${DBUS_ARCH_INCLUDE_DIR})
-	set(DBUS_LIBRARIES ${DBUS_LIB})
-	set(HAVE_DBUS "1")
-else()
-	set(HAVE_DBUS "0")
-endif()

cmake/Modules/FindGio.cmake

@@ -0,0 +1,27 @@
+# - Try to find Gio
+# Once done this will define
+#
+#  GIO_FOUND - system has Gio
+#  GIO_INCLUDE_DIRS - the Gio include directory
+#  GIO_LIBRARIES - the libraries needed to use Gio
+#  GIO_DEFINITIONS - Compiler switches required for using Gio
+
+# Use pkg-config to get the directories and then use these values
+# in the find_path() and find_library() calls
+find_package(PkgConfig)
+pkg_check_modules(PC_GIO gio-2.0)
+
+set(GIO_DEFINITIONS ${PC_GIO_CFLAGS})
+
+find_path(GIO_INCLUDE_DIRS gio.h PATHS ${PC_GIO_INCLUDEDIR} ${PC_GIO_INCLUDE_DIRS} PATH_SUFFIXES glib-2.0/gio/)
+find_library(GIO_LIBRARIES NAMES gio-2.0 libgio-2.0 PATHS ${PC_GIO_LIBDIR} ${PC_GIO_LIBRARY_DIRS})
+mark_as_advanced(GIO_INCLUDE_DIRS GIO_LIBRARIES)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Gio REQUIRED_VARS GIO_LIBRARIES GIO_INCLUDE_DIRS)
+
+if(GIO_FOUND)
+  set(HAVE_DBUS "1")
+else()
+  set(HAVE_DBUS "0")
+endif()