python,python3: export mk files outside of python package dirs

Since `lang/python` is it's own folder of Python packages
(for both Python 2 & 3), and these build rules are needed
in a lot of packages [especially Python packages],
putting them here makes sense architecturally,
to be shared.

This also helps get rid of the `include_mk` construct
which relies on OpenWrt core to provide, and seems
like a broken design idea that has persisted for a while.
Reason is: it requires that Python 2/3 be built to provide
these mk files for other Python packages,
which seems like a bad idea.

Long-term, there could be an issue where some other feeds
would require these mk files [e.g. telephony] for
some Python packages.
We'll see how we handle this a bit later.

For now we limit this to this feed.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python/python-package-install.sh

@@ -0,0 +1,82 @@
+#!/bin/sh
+set -e
+
+process_filespec() {
+	local src_dir="$1"
+	local dst_dir="$2"
+	local filespec="$3"
+	echo "$filespec" | (
+	IFS='|'
+	while read fop fspec fperm; do
+		local fop=`echo "$fop" | tr -d ' \t\n'`
+		if [ "$fop" = "+" ]; then
+			if [ ! -e "${src_dir}${fspec}" ]; then
+				echo "File not found '${src_dir}${fspec}'"
+				exit 1
+			fi
+			dpath=`dirname "$fspec"`
+			if [ -z "$fperm" ]; then
+				dperm=`stat -c "%a" ${src_dir}${dpath}`
+			fi
+			mkdir -p -m$dperm ${dst_dir}${dpath}
+			echo "copying: '$fspec'"
+			cp -fpR ${src_dir}${fspec} ${dst_dir}${dpath}/
+			if [ -n "$fperm" ]; then
+				chmod -R $fperm ${dst_dir}${fspec}
+			fi
+		elif [ "$fop" = "-" ]; then
+			echo "removing: '$fspec'"
+			rm -fR ${dst_dir}${fspec}
+		elif [ "$fop" = "=" ]; then
+			echo "setting permissions: '$fperm' on '$fspec'"
+			chmod -R $fperm ${dst_dir}${fspec}
+		fi
+	done
+	)
+}
+
+src_dir="$1"
+dst_dir="$2"
+python="$3"
+mode="$4"
+filespec="$5"
+
+process_filespec "$src_dir" "$dst_dir" "$filespec" || {
+	echo "process filespec error-ed"
+	exit 1
+}
+
+if [ "$mode" == "sources" ] ; then
+	# Copy only python source files
+	find $dst_dir -not -type d -not -name "*\.py" | xargs rm -f
+
+	# Delete empty folders (if the case)
+	if [ -d "$dst_dir/usr" ] ; then
+		find $dst_dir/usr -type d | xargs rmdir --ignore-fail-on-non-empty
+		rmdir --ignore-fail-on-non-empty $dst_dir/usr
+	fi
+	exit 0
+fi
+
+# XXX [So that you won't goof as I did]
+# Note: Yes, I tried to use the -O & -OO flags here.
+#       However the generated byte-codes were not portable.
+#       So, we just stuck to un-optimized byte-codes,
+#       which is still way better/faster than running
+#       Python sources all the time.
+$python -m compileall -d '/' $dst_dir || {
+	echo "python -m compileall err-ed"
+	exit 1
+}
+
+# Delete source files and pyc [ un-optimized bytecode files ]
+# We may want to make this optimization thing configurable later, but not sure atm
+find $dst_dir -type f -name "*\.py" | xargs rm -f
+
+# Delete empty folders (if the case)
+if [ -d "$dst_dir/usr" ] ; then
+	find $dst_dir/usr -type d | xargs rmdir --ignore-fail-on-non-empty
+	rmdir --ignore-fail-on-non-empty $dst_dir/usr
+fi
+
+exit 0