Update docs 6

1. Added example of squish!
2. Added example of remove
3. Added example of remove!
4. Added test case for removal of multiple occurrences of pattern.
I don't know why that came in the diff. As you can see I have just one line break above  test_constantize. 

![screen shot 2014-11-06 at 07 22 13](https://cloud.githubusercontent.com/assets/946527/4929737/a6ad6fc6-6557-11e4-98db-448f1893e3be.png)