New package: hunspell-ru (#846)

Russian dictionary for Hunspell, a trivial copy-paste job based on
hunspell-en-us.

The package name is `hunspell-ru` because that's what the Ubuntu equivalent is
named.

packages/hunspell-ru/build.sh

@@ -0,0 +1,20 @@
+TERMUX_PKG_HOMEPAGE=https://hunspell.github.io
+TERMUX_PKG_DESCRIPTION="Russian dictionary for hunspell"
+TERMUX_PKG_VERSION=2017.03.03
+TERMUX_PKG_REVISION=1
+TERMUX_PKG_PLATFORM_INDEPENDENT=yes
+
+termux_step_make_install () {
+	mkdir -p $TERMUX_PREFIX/share/hunspell/
+	# On checksum mismatch the files may have been updated:
+	#  https://cgit.freedesktop.org/libreoffice/dictionaries/log/ru_RU/ru_RU.aff
+	#  https://cgit.freedesktop.org/libreoffice/dictionaries/log/ru_RU/ru_RU.dic
+	# In which case we need to bump version and checksum used.
+	termux_download https://cgit.freedesktop.org/libreoffice/dictionaries/plain/ru_RU/ru_RU.aff \
+			$TERMUX_PREFIX/share/hunspell/ru_RU.aff \
+                        709cf9b41208961226e995a3ab75a2da834aaf4f9707cb87cbb37d4943b6a50d
+	termux_download https://cgit.freedesktop.org/libreoffice/dictionaries/plain/ru_RU/ru_RU.dic \
+			$TERMUX_PREFIX/share/hunspell/ru_RU.dic \
+                        c0d81126b0a905ccc6fd891c923b43d39b4ce449da5a333859229354c510168f
+	touch $TERMUX_PREFIX/share/hunspell/ru_RU.{aff,dic}
+}