Extend startup with logging and failure handling on 0.9.x versions

Before this patch users may ran into a local installation older than 0.9.x, this patch
ensures that the version is compatible to be preffered over the global version. If the
local version is to old (<0.10.0) the global version will be used instead. If this is
the case a warn message gets displayed to the user.

Additionally added informational logging within the verbose mode if a local version gets
preferred.

solves #317

Author: wzrdtales

bin/db-migrate

@@ -1,23 +1,36 @@
 #!/usr/bin/env node
 
 var resolve = require( 'resolve' );
+var log = require( '../lib/log.js' );
 
 process.title = 'db-migrate';
 
+if ( process.argv.indexOf( '--verbose' ) !== -1 || process.argv.indexOf( '-v' ) !== -1 )
+  global.verbose = true;
+
 resolve( 'db-migrate', {
 
-  basedir: process.cwd()
+basedir: process.cwd()
 }, function ( error, localModule ) {
 
-  var DBMigrate, dbmigrate;
+var DBMigrate, dbmigrate;
+
+if ( error ) {
+  DBMigrate = require( '../' );
+}
+else {
+  DBMigrate = require( localModule );
+  log.verbose( 'Detected and using the projects local version of db-migrate. ' +
+    '\'' + localModule + '\'');
+}
+
+if ( typeof( DBMigrate.getInstance ) !== 'function' ) {
+  DBMigrate = require( '../' );
 
-  if ( error ) {
-    DBMigrate = require( '../' );
-  }
-  else {
-    DBMigrate = require( localModule );
-  }
+  log.warn( 'Using global instead of local detected version as you have a ' +
+    'version older than 0.10.0 in your projects package.json!' );
+}
 
-  dbmigrate = DBMigrate.getInstance();
-  dbmigrate.run();
+dbmigrate = DBMigrate.getInstance();
+dbmigrate.run();
 } );