Add possibility to run selected code from a temporary file 

"context.getFileWithCode()" can be used in grammars instead of
"context.getCode()" allowing to run selected code with languages that
don't have interpreters like "php -r". Tested with PHP (see example in
grammars.coffee with PHP language)
Refactoring temporary files creation

- Renaming temporary files functions
- Moving deleteTempFiles and createTempFileWithCode in grammar-utils
- Add GrammarUtils.PHP
- Modify grammar for PHP
- Clean code context
Better error handling, Clean code, Test PHP header

- :lipstick: Removing a blank line in code-context
- :lipstick: Clean some code (use of unless and co)
- Improve error handling with try/catch
- Errors are displayed in a Pane (like other errors of the package)
- Add a test before adding <?php
Merge pull request #229 from zedentox/run-selection-in-temp-file

Add possibility to run selected code from a temporary file instead of passing code in args