Qtbindings clipboard conflict
In the clipboard package, I see pandas is using pyperclip

the problem is that pyperclip uses PyQt4 when deciding to use Qt for the linux clipboard, which can create a conflict if trying to embed pandas into a PyQt5 or PySide application for example

I think the simplest solution is to use [qtpy from the Spyder](https://github.com/spyder-ide/qtpy) team, so replace:

```python
from PyQt4.QtGui import QApplication
```

with

```python
from qtpy.QtWidgets import QApplication
```

I am currently working on a PyQt5 based pandas data visualization program and this is a problem I have encountered in the past.