bootstrap: Run linguas.sh in bootstrap epilogue

Heretofore, linguas.sh had to be run by the user and a common mistake
made when building GRUB was to not run the command. By adding it to
the bootstrap epilogue it will by default get run at the end of the
bootstrap script. The user no longer needs to remember to run it.
If the --skip-po option is passed to bootstrap, do not run linguas.sh.
This allows for bootstrap to be run without updating the translations,
which might be desired in the future if we track po files so that
translations can be used as they were at time of release.

Update INSTALL file to reflect that it is no longer necessary to run
linguas.sh. Also, fix a list numbering error.

Fixes: 9f73ebd49b (* INSTALL: Document linguas.sh.)

Signed-off-by: Glenn Washburn <development@efficientek.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

bootstrap.conf

@@ -63,7 +63,7 @@ checkout_only_file=
 copy=true
 vc_ignore=
 
-SKIP_PO=t
+SKIP_PO=n
 
 # Build prerequisites
 buildreq="\
@@ -108,4 +108,10 @@ bootstrap_post_import_hook () {
 
 bootstrap_epilogue () {
   mv INSTALL.grub INSTALL
+
+  # Update translation files and create LINGUAS file used to determine
+  # the set of languages used to translate.
+  if [ "x$SKIP_PO" = "xn" ]; then
+    ./linguas.sh
+  fi
 }