Check if compile.php target directories exist, exit if not

If it's not run from the correct directory, a spew of warnings appear

Add done message and also one if not running on the CLI

Change-Id: Iec508acf4216aba7d084bb57156b87bfb117ff4a

data/fontrepo/scripts/compile.php

@@ -1,7 +1,11 @@
 <?php
 
 if ( isset( $_SERVER['REQUEST_METHOD'] ) ) {
-	exit();
+	exit( "compile.php should be run from the command line\n" );
+}
+
+if ( !is_dir( '../fonts/' ) ) {
+	exit( "compile.php should be run from the data/fontrepo/scripts directory\n" );
 }
 
 $list = array();
@@ -97,3 +101,5 @@ $js = <<<JAVASCRIPT
 
 JAVASCRIPT;
 file_put_contents( '../../../resources/js/ext.uls.webfonts.repository.js', $js );
+
+echo "Done.\n";