gnu: Add rust-cargo-util-0.1.

* gnu/packages/crates-io.scm (rust-cargo-util-0.1): New variable.

Signed-off-by: Maxim Cournoyer <maxim.cournoyer@gmail.com>

gnu: gstreamer: Do not reference Python.

* gnu/packages/gstreamer.scm (gstreamer) [native-inputs]: Replace
python-wrapper with python.
[arguments]: List python in #:disallowed-references.  Add a
'do-not-capture-python phase.

gnu: ibus-minimal: Disable GTK 2 support.

* gnu/packages/ibus.scm (ibus-minimal) [configure-flags]: Add
'--disable-gtk2'.
[inputs]: Remove gtk+-2.

gnu: ibus-minimal: Move Python support to ibus.

This reduces the size of ibus-minimal from 1446.7 MiB to 1222.3 MiB.

* gnu/packages/ibus.scm (ibus-minimal): Remove "--enable-python-library" flag.
[phases] {wrap-with-additional-paths}: Do not wrap GUIX_PYTHONPATH.
[inputs]: Move python-pygobject, python and python-dbus to...
(ibus) [inputs]: ... here.
[arguments]: Add --enable-python-library configure flag and override
wrap-with-additional-paths phase.

gnu: speex: Update to 1.2.1.

* gnu/packages/xiph.scm (speex): Update to 1.2.1.

gnu: Remove lash.

* gnu/packages/audio.scm (lash): Delete variable.

gnu: fluidsynth: Update to 2.3.1.

* gnu/packages/audio.scm (fluidsynth): Update to 2.3.1.

gnu: fluidsynth: Remove lash input.

* gnu/packages/audio.scm (fluidsynth) [inputs]: Remove lash.

gnu: rust-ryu-1: Update to 1.0.12.

* gnu/packages/crates-io.scm (rust-ryu-1): Update to 1.0.12.
[cargo-development-inputs]: Replace rust-rand-0.7 with 0.8,
rust-rand-xorshift-0.2 with 0.3.

gnu: rust-pin-project-0.4: Update to 0.4.30.

* gnu/packages/crates-io.scm (rust-pin-project-0.4): Update to 0.4.30.
[source]: Add snippet to relax dependency requirements.
[arguments]: Don't skip tests.
[cargo-development-inputs]: Add rust-rustversion-1, rust-ryu-1,
rust-serde-json-1, rust-toml-0.5, rust-trybuild-1.
(rust-pin-project-internal-0.4): Update to 0.4.30.
[cargo-development-inputs]: Add rust-rustversion-1.

gnu: rust-utf-8-0.7: Update to 0.7.6.

* gnu/packages/crates-io.scm (rust-utf-8-0.7): Update to 0.7.6.

gnu: rust-rand-pcg-0.3: Update to 0.3.1.

* gnu/packages/crates-io.scm (rust-rand-pcg-0.3): Update to 0.3.1.

gnu: rust-num-rational-0.2: Update to 0.2.4.

* gnu/packages/crates-io.scm (rust-num-rational-0.2): Update to 0.2.4.

gnu: rust-new-debug-unreachable-1: Update to 1.0.4.

* gnu/packages/crates-io.scm (rust-new-debug-unreachable-1): Update to 1.0.4.

gnu: rust-libm-0.2: Update to 0.2.6.

* gnu/packages/crates-io.scm (rust-libm-0.2): Update to 0.2.6.

gnu: rust-futf-0.1: Update to 0.1.5.

* gnu/packages/crates-io.scm (rust-futf-0.1): Update to 0.1.5.

gnu: rust-encoding-rs-0.8: Update to 0.8.31.

* gnu/packages/crates-io.scm (rust-encoding-rs-0.8): Update to 0.8.31.

gnu: rust-decimal-2: Update to 2.1.0.

* gnu/packages/crates-io.scm (rust-decimal-2): Update to 2.1.0.

gnu: rust-tendril-0.4: Update to 0.4.3.

* gnu/packages/crates-io.scm (rust-tendril-0.4): Update to 0.4.3.
[arguments]: Don't skip build.

gnu: rust-string-cache-codegen-0.5: Update to 0.5.2.

* gnu/packages/crates-io.scm (rust-string-cache-codegen-0.5: Update to
0.5.2.
[cargo-inputs]: Replace rust-phf-generator-0.8 with 0.10,
rust-phf-shared-0.8 with 0.10.