capabilities: Add support for Linux capabilities(7)

This adds capabilities for start-stop-daemon by adding --capabilities
option. As a result, the user can specify the inheritable, ambient and
bounding set by define capabilities in the service script.

This fixes #314.

.github/workflows/ci-alpine-linux.yml

@@ -15,7 +15,9 @@ jobs:
             meson \
             pkgconf \
             linux-pam \
-            linux-pam-dev
+            linux-pam-dev \
+            libcap \
+            libcap-dev
       - name: checkout
         uses: actions/checkout@v2
       - run: meson setup builddir/

.github/workflows/ci-ubuntu.yml

@@ -9,7 +9,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - run: sudo apt-get update -q
-    - run: sudo apt-get install -q -y build-essential libpam-dev meson
+    - run: sudo apt-get install -q -y build-essential libpam-dev meson libcap-dev
     - run: meson setup builddir/
       env:
         CC: gcc
@@ -23,7 +23,7 @@ jobs:
     steps:
     - uses: actions/checkout@v2
     - run: sudo apt-get update -q
-    - run: sudo apt-get install -q -y build-essential clang libpam-dev meson
+    - run: sudo apt-get install -q -y build-essential clang libpam-dev meson libcap-dev
     - run: meson setup builddir/
       env:
         CC: clang