Now escaping is actually done automatically for expression statements.

## Code improvement

Implementing the feature didn't require a lot of code change (basically just removing the code keeping the backward compatible mode). However, the code required some cleaning. The comments/JSDoc as well have been improved.

- implementation of the feature (in the Statements class)
- implementation and tests for the modifier implementation: notably adding the documentation for the "arg" argument (corresponding to the "options" argument of the String utility, see next point)
- implementation and tests for the related String utility implementation: notably it's easier now to understand how the "options" argument works

## Internal code update regarding the change

Expression intentionally outputting HTML have been identified and changed to disable the automatic escaping.

Concerned pieces of code are:

- some tests
- some widgets' templates
- the tester application
- the debug tools (contextual menu)

## Unrelated fixes

- the aria.utils.Bridge class can now actually load the development files of the framework (used for the debug tools).
- in JSDoc comments: some parameters were documented with the @param[in] syntax, which is not understood by the JSDoc parser we use, so I removed this syntax in favor of the usual one @param