Support format and variable pars for printf()

https://github.com/pikasTech/pikascript/commit/6acc0f9ecd11fbecb81219d14c49ee0e6adaa426

Example:
``` python
import PikaStdLib

print('test')
print('my name is', 'old wang', 'my age is', 43)
print('format: %s,%04d,%.2f' % ('test', 123, 15.5))
```