Replace unsafe perl meta-script with sed script

It's easier to do quoting at least mediocre-right in sed than in perl;
eg. with Perl, even e-mail address was causing quoting breakage due to
the at sign.

src/include/build.sh

@@ -70,22 +70,22 @@ _expand_tokens() {
             ini lskeys "$section" \
               | while read varname;
                 do
-                    varvalue="$(ini 1value "$section:$varname" | sed -e 's/\$/\\$/' )"
+                    varvalue="$(ini 1value "$section:$varname" | _qfs )"
                     echo "s|$varname|$varvalue|g;"
                     debug_var varname varvalue
                 done
         done
-        echo "s|__MKIT_PROJ_NAME__|$(ini 1value project:name)|g;"
-        echo "s|__MKIT_PROJ_CODENAME__|$(ini 1value project:codename)|g;"
-        echo "s|__MKIT_PROJ_PKGNAME__|$(ini 1value project:pkgname)|g;"
-        echo "s|__MKIT_PROJ_TAGLINE__|$(ini 1value project:tagline)|g;"
-        echo "s|__MKIT_PROJ_MAINTAINER__|$(ini 1value project:maintainer)|g;"
-        echo "s|__MKIT_PROJ_VCS_BROWSER__|$(ini 1value project:vcs_browser)|g;"
-        echo "s|__MKIT_PROJ_GIT_LASTHASH__|$(git_lasthash)|g;"
-        echo "s|__MKIT_PROJ_VERSION__|$(semver)|g;"
+        echo "s|__MKIT_PROJ_NAME__|$(ini 1value project:name | _qfs)|g;"
+        echo "s|__MKIT_PROJ_CODENAME__|$(ini 1value project:codename | _qfs)|g;"
+        echo "s|__MKIT_PROJ_PKGNAME__|$(ini 1value project:pkgname | _qfs)|g;"
+        echo "s|__MKIT_PROJ_TAGLINE__|$(ini 1value project:tagline | _qfs)|g;"
+        echo "s|__MKIT_PROJ_MAINTAINER__|$(ini 1value project:maintainer | _qfs)|g;"
+        echo "s|__MKIT_PROJ_VCS_BROWSER__|$(ini 1value project:vcs_browser | _qfs)|g;"
+        echo "s|__MKIT_PROJ_GIT_LASTHASH__|$(git_lasthash | _qfs)|g;"
+        echo "s|__MKIT_PROJ_VERSION__|$(semver | _qfs)|g;"
         echo "s|__MKIT_SELF_VERSION__|$MKIT_VERSION|g;"
     } >> "$script"
-    perl -wp "$script" || die "_expand_tokens failed"
+    sed -f "$script" || die "_expand_tokens failed"
     rm "$script"
 }
 
@@ -100,6 +100,15 @@ _guess_ftype() {
     esac
 }
 
+_qfs() {
+    #
+    # Quote for our sed scipt's RHS
+    #
+    sed '
+        s:\\:\\\\:g
+        s:|:\\|:g
+    '
+}
 
 build() {
     #