get rid of binded project to replace unbinded cloud application

This PR is used to get rid of binded project to replace unbinded cloud application of the merged feature of application replacement.
- If the user drag and drop a project which has binded with a cloud application, firstly a wizard with choices is presented.
![issue4_replaceunbindedappwithbindedproject](https://cloud.githubusercontent.com/assets/7316500/4333436/406b48ec-3fe0-11e4-9860-0a24be07c2d8.PNG)
Then choose to replace the unbinded cloud application 'sshsample-sjw0919', a confirmation dialog is shown.
![issue4_replaceunbindedappwithbindedproject_cd](https://cloud.githubusercontent.com/assets/7316500/4333439/4881a6d4-3fe0-11e4-8b18-7df1395b894c.PNG)
Finally press ok, then a information dialog is presented and the replacement operation is terminated.
![issue4_replaceunbindedappwithbindedproject_infodialog](https://cloud.githubusercontent.com/assets/7316500/4333442/4ef1d9f8-3fe0-11e4-83fd-9590cce9b110.PNG)

- The codes of this PR is to make a judgement about whether the given project has a binded cloud application, if it does then a information dialog 
presents and the replacement process is terminated.If without these logics, this operation may trigger the cloud application to be deleted in CF.