Automatically install pkg-config when needed.

Every package checked with pkg-config implicitly requires it as a
dependency. Add it as a dependency when installing the pkg-config
module.

chocpkg/chocpkg

@@ -52,7 +52,7 @@ basic_setup
 . "$CHOCPKG_ROOT/buildenv.sh"
 
 dependencies() {
-    DEPENDENCIES="$*"
+    DEPENDENCIES+="$*"
 }
 
 # set_pkgconfig_paths sets the values of the PKG_CONFIG_PATH and

chocpkg/modules/check_pkgconfig.sh

@@ -1,6 +1,10 @@
 
 check_pkgconfig::init() {
     PKGCONFIG_NAME=$1
+
+    # If we're using pkg-config to check, we need to install pkg-config
+    # first.
+    dependencies pkg-config
 }
 
 # Function that returns true if the package is installed.