gstreamer: Re-export the paste crate for the gst_plugin_define! macro

And only depend on the paste crate if the subclass feature is requested.

gstreamer/Cargo.toml

@@ -27,7 +27,7 @@ muldiv = "0.2"
 serde = { version = "1.0", optional = true }
 serde_bytes = { version = "0.11", optional = true }
 serde_derive = { version = "1.0", optional = true }
-paste = "0.1"
+paste = { version = "0.1", optional = true }
 
 [build-dependencies.rustdoc-stripper]
 version = "0.1"
@@ -49,4 +49,4 @@ purge-lgpl-docs = ["rustdoc-stripper"]
 dox = ["gstreamer-sys/dox", "glib/dox", "futures", "ser_de"]
 futures = ["futures-core-preview"]
 ser_de = ["num-rational/serde", "serde", "serde_bytes", "serde_derive"]
-subclassing = ["glib/subclassing"]
+subclassing = ["glib/subclassing", "paste"]

gstreamer/src/lib.rs

@@ -23,6 +23,9 @@ pub extern crate glib_sys;
 pub extern crate gobject_sys;
 #[doc(hidden)]
 pub extern crate gstreamer_sys as gst_sys;
+#[doc(hidden)]
+#[cfg(feature = "subclassing")]
+pub extern crate paste;
 
 #[macro_use]
 #[doc(hidden)]

gstreamer/src/subclass/plugin_1_14.rs

@@ -60,7 +60,7 @@ macro_rules! gst_plugin_define(
                 }
             }
 
-            paste::item! {
+            $crate::paste::item! {
                 #[no_mangle]
                 pub unsafe extern "C" fn [<gst_plugin_ $name _register>] () {
                     let _ = plugin_register_static();