Change sources getting method.

- Rather than defining the urls where they are gotten (python sysa,
  python sysc, inside sysc), a spec file is now used that is easily
  interpretable and tool-independent.
- This is interpreted by rootfs.py and inside sysc.
- This is also used to make sources available and extract sources.
- Manual dirname selection is no longer required as is tarball renaming
  upon download - all of this is handled automatically.

Fixes #188

sysa/e2fsprogs-1.45.7/e2fsprogs-1.45.7.sh

@@ -2,16 +2,12 @@
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-src_unpack() {
-    default
-
-    # Get remaining utf files
-    cp ${DISTFILES}/*.txt ${pkg}/
-}
-
 src_prepare() {
     default
 
+    # Get UTF txt files
+    cp ../*.txt .
+
     # Rebuild libtool files
     rm config/config.guess config/config.sub config/ltmain.sh
     libtoolize -i

sysa/e2fsprogs-1.45.7/sources

@@ -0,0 +1,8 @@
+https://mirrors.edge.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/v1.45.7/e2fsprogs-1.45.7.tar.gz 340e9de42a12d0c26dd7527e9ef055ac85586de5c61f6273ae19f88d04e55804
+https://www.unicode.org/Public/11.0.0/ucd/CaseFolding.txt 64f117a4749dd4a1b6c54277f63f6cf1e0eb45d290cbedaf777fbe71b8880885
+https://www.unicode.org/Public/11.0.0/ucd/DerivedAge.txt eb115a5de9a32c9ad447d6ea1cddcadb53d47f6cbc2521f3fe0bebb040c39866
+https://www.unicode.org/Public/11.0.0/ucd/extracted/DerivedCombiningClass.txt 11c8bd81ecbede4d67c7b5b693a471647d5401956707c639ae053b836cc7f5da
+https://www.unicode.org/Public/11.0.0/ucd/DerivedCoreProperties.txt 3406825d64564bf2a37031c36a3e0f99d708aa17595b81f8b539d0f3d1a3923f
+https://www.unicode.org/Public/11.0.0/ucd/NormalizationCorrections.txt c9ffe32e616fa085246644c2351c525788fac363872491185dab7d5ce69fefa9
+https://www.unicode.org/Public/11.0.0/ucd/NormalizationTest.txt 0fdfc17093dd5482f8089cb11dcd936abdba34c4c9c324e5b8a4e5d8f943f6d3
+https://www.unicode.org/Public/11.0.0/ucd/UnicodeData.txt 4997a3196eb79b4d0d6b8384560f6aeb46a062693f0abd5ba736abbff7976099