Check that $mode in InputArgument::__construct() is not below 1 to actually look if any of the flags are set.
Check that $mode in InputOption::__construct() is not below 1 to actually look if any of the flags are set.
Check for the correct parameter type, as in InputOption (integer).
InputArgumentTest: Added test for negative integer $mode parameter input in constructor.
InputOptionTest: Added test for negative integer $mode parameter input in constructor.
To keep language consistent, three methods were changed in InputOption:
* `InputOption::acceptParameter()` -> `InputOption::acceptValue()`
* `InputOption::isParameterRequired()` -> InputOption::isValueRequired()`
* `InputOption::isParameterOptional()` -> `InputOption::isValueOptional()`
The InputDefinition::asXml() method was also modified to update the `accept_value` and `is_value_required` attributes.