Support for p7zip

Based on andrew-d/static-binaries#23 suggestion

README.md

@@ -8,6 +8,7 @@ Static binaries for common tools
 | nano            | 4.7        | nano     | [.tar.xz](https://www.nano-editor.org/dist/v4/nano-${VERSION}.tar.xz)  |
 | squashfs        | 4.4        | mksquashfs     | [.tar.gz](https://github.com/plougher/squashfs-tools/archive/${VERSION}.tar.gz)  |
 | wget            | 1.20.3     | wget     | [.tar.gz](https://ftp.gnu.org/gnu/wget/wget-${VERSION}.tar.gz)  |
+| p7zip           | 16.02      | 7za      | [.tar.gz](https://github.com/btolab/p7zip/archive/${VERSION}.tar.gz)  |
 
 # Build
 If you want to build the binaries by yourself, just execute:

build/software/p7zip/Dockerfile

@@ -0,0 +1,14 @@
+FROM localhost:5000/buildsystem
+
+ARG SOURCE
+
+RUN curl -LO $SOURCE
+
+RUN set -ex; \
+    tar xvf *; \
+    cd */; \
+        LDFLAGS="-static" \
+            make 7za 7zr sfx -j$(nproc --all); \
+        strip bin/7za bin/7zr bin/7zCon.sfx; \
+        cp bin/7za bin/7zr bin/7zCon.sfx /out/; \
+    rm -Rf $WORKDIR/*

build/software/p7zip/info

@@ -0,0 +1 @@
+VERSION="| head -2 | grep -i copyright | cut -d: -f1 | cut -d" " -f4"