fix defect https://github.com/beautify-web/js-beautify/issues/495#

- correct the call to the print_newline.
- add another condition to enable print space before in case of unary
operators
- port fix to python
- add test cases to fix
remove unneeded new line
Merge pull request #503 from ashamza/fix#495

Fix pre-increment and pre-decrement formatting issues (#495)
Merge remote-tracking branch 'origin/master' into gh-pages