phosh/squeekboard: new aport (!523)

Squeekboard is going to replace virtboard in Phosh. However, it requires
Rust which hasn't yet been packaged on Alpine Linux for aarch64. So for
now, keep virtboard as the default (it still works fine) and update it
to the latest commit (see follow-up patch), but also introduce
squeekboard so we can test it and eventually enabled it for aarch64 and
replace virtboard.

phosh/squeekboard/APKBUILD

+# Contributor: Bart Ribbers <bribbers@disroot.org>
+# Maintainer: Bart Ribbers <bribbers@disroot.org>
+pkgname=squeekboard
+pkgver=0_git20190723
+pkgrel=0
+_commit="4b66add65fa7d3875596c108430699a44d98f50e"
+pkgdesc="The final Phosh keyboard"
+arch="all"
+url="https://source.puri.sm/Librem5/squeekboard"
+license="GPL-3.0-or-later"
+depends=""
+makedepends="meson ninja rust glib-dev wayland-protocols wayland-dev gtk+3.0-dev libcroco-dev"
+checkdepends="xvfb-run"
+source="$pkgname-$pkgver.tar.gz::https://source.puri.sm/Librem5/$pkgname/-/archive/$_commit.tar.gz"
+subpackages="$pkgname-lang"
+builddir="$srcdir/$pkgname-$_commit"
+
+build() {
+	meson . _build --prefix=/usr
+	ninja -C _build
+}
+
+check() {
+	xvfb-run ninja -C _build test
+}
+
+package() {
+	DESTDIR="$pkgdir" ninja -C _build install
+}
+sha512sums="5f3f6b1b5f552a8216dffb3e9322d0ea94bb9e179e292efd69a5b281bcd7f67b16e2aaafa3863ada3703200274a591e825535f21da79b4fb97731c8576269896  squeekboard-0_git20190723.tar.gz"