Moved constants out of misuzu.php.

tools/migrate

@@ -1,13 +1,13 @@
 #!/usr/bin/env php
 <?php
-use Index\Db\Migration\FsDbMigrationRepo;
-
 require_once __DIR__ . '/../misuzu.php';
 
-try {
-    touch(MSZ_ROOT . '/.migrating');
-    chmod(MSZ_ROOT . '/.migrating', 0777);
+$lockPath = $msz->dbCtx->getMigrateLockPath();
+if(is_file($lockPath))
+    die('A migration script is already running.' . PHP_EOL);
 
+touch($lockPath);
+try {
     echo 'Creating migration manager...' . PHP_EOL;
     $manager = $msz->dbCtx->createMigrationManager();
 
@@ -29,6 +29,8 @@ try {
     }
 
     echo PHP_EOL;
+} catch(Exception $ex) {
+    var_dump($ex);
 } finally {
-    unlink(MSZ_ROOT . '/.migrating');
+    unlink($lockPath);
 }

tools/migrate-override-toggle

@@ -0,0 +1,12 @@
+#!/usr/bin/env php
+<?php
+require_once __DIR__ . '/../misuzu.php';
+
+$lockPath = $msz->dbCtx->getMigrateLockPath();
+if(is_file($lockPath)) {
+    printf('Removing migration lock...%s', PHP_EOL);
+    unlink($lockPath);
+} else {
+    printf('Setting migration lock...%s', PHP_EOL);
+    touch($lockPath);
+}