Minor changes

- Made all dialogs open in parent's center
- The current object your are editing is displayed in the dialog's
titles
![ws3](https://f.cloud.github.com/assets/2184244/1950990/c5579f4a-8165-11e3-8881-6d9cc4787e23.PNG)
![ws4](https://f.cloud.github.com/assets/2184244/1950993/c946121c-8165-11e3-9ff8-97affc93defa.PNG)