Drop websql and store plain file in dataPath

1. Drop websql because it's hard to debug and maintain
2. Use nedb as our db backend (nosql friendly API). Because nedb will
create plain file as db in dataPath, we can debug Atraci more easily
3. fix a bug that when creating playlist, if you type enter (on mac),
then Atraci would jump to white screen without any reason and

coffee/_history.coffee

@@ -1,55 +1,65 @@
-# Init preparation (should be improved later)
-db.transaction (tx) ->
-  tx.executeSql(
-    'CREATE TABLE IF NOT EXISTS history ' +
-    '(artist, title, cover_url_medium, cover_url_large, last_played)'
-  )
-
 class History
   @clear: (success) ->
-    db.transaction (tx) ->
-      tx.executeSql 'DROP TABLE history'
-      success?()
+    db.history.remove({}, { multi: true }, (error) ->
+      if error
+        console.log("History.clear remove erorr :")
+        console.log(error)
+        success?()
+      else
+        success?()
+    )
 
   @addTrack: (artist, title, cover_url_medium, cover_url_large) ->
     unix_timestamp = Math.round((new Date()).getTime() / 1000)
-    db.transaction (tx) ->
-      tx.executeSql(
-        'CREATE TABLE IF NOT EXISTS history ' +
-        '(artist, title, cover_url_medium, cover_url_large, last_played)'
-      )
-
-      tx.executeSql(
-        'DELETE FROM history WHERE artist = ? and title = ?', [artist, title]
-      )
-
-      tx.executeSql(
-        'INSERT INTO history ' +
-        '(artist, title, cover_url_medium, cover_url_large, last_played) ' +
-        'VALUES (?, ?, ?, ?, ?)',
-        [artist, title, cover_url_medium, cover_url_large, unix_timestamp]
-      )
+    db.history.remove({
+      artist: artist,
+      title: title
+    }, {}, (error, numRemoved) ->
+      if error
+        console.log("History.addTrack remove erorr :")
+        console.log(error)
+      else
+        db.history.insert({
+          artist: artist,
+          title: title,
+          cover_url_medium: cover_url_medium,
+          cover_url_large: cover_url_large,
+          last_played: unix_timestamp
+        }, (error) ->
+          if error
+            console.log("History.addTrack insert erorr :")
+            console.log(error)
+        )
+    )
 
   @removeTrack: (artist, title) ->
-    db.transaction (tx) ->
-      tx.executeSql(
-        'DELETE FROM history WHERE artist = ? and title = ?', [artist, title]
-      )
+    db.history.remove({
+      artist: artist,
+      title: title
+    }, {}, (error) ->
+      if error
+        console.log("History.removeTrack remove erorr :")
+        console.log(error)
+    )
 
   @getTracks: (success) ->
-    tracks = []
-    db.transaction (tx) ->
-      tx.executeSql(
-        'SELECT * FROM history ORDER BY last_played DESC LIMIT 150', [],
-        (tx, results) ->
-          i = 0
-          while i < results.rows.length
-            tracks.push results.rows.item(i)
-            i++
-          success? tracks
-      )
+    db.history.find({}).sort({
+      last_played: -1
+    }).limit(150).exec((error, foundTracks) ->
+      if error
+        console.log("History.getTracks find erorr :")
+        console.log(error)
+        success?([])
+      else
+        success?(foundTracks)
+    )
 
   @countTracks: (success) ->
-    db.transaction (tx) ->
-      tx.executeSql 'SELECT COUNT(*) AS cnt FROM history', [], (tx, results) ->
-        success? results.rows.item(0).cnt
+    db.history.count({}, (error, count) ->
+      if error
+        console.log("History.countTracks count erorr :")
+        console.log(error)
+        success?(0)
+      else
+        success?(count)
+    )