Closing tags fix for #228

Fix for #228.

- Rewrite php_closing_tag fixer to use tokens
- Fix closing tags in code with short open tag as well, works only if short_open_tag is enabled
- Extend utests for php_closing_tag fixer
- Add Tokens::findGivenKind method to find given tokens occurrence
- Try to enabled short_open_tag in php.ini
`<?php echo "foo"; ?>` -> `<?php echo "foo";`
`<?php echo "foo"; ?> bar` -> `<?php echo "foo"; ?> bar`
`<?=$me;?>` -> `<?=$me;`
`<?=$me;?> is happy.` -> `<?=$me;?> is happy.`

Which one would you change and why ?