Merge pull request bootboxjs#740 from tiesont/master

Adds hooks for Bootstrap's modal events

Removes `:first` selector

Fixes incorrect value validation for step attribute

Updates patch version to 5.3.2

Modifies dialog to only process button callback if it has been defined

Modifies dialog to only process button callback if it has been defined; see bootboxjs#705

Updates bootbox.all.js

Updates minified files

Adds rows as an option when using a textarea prompt

Updates tests

- Adds default value for scrollable option
- Updates tests

Adds Tamil locale

Version bump for new locale.

Regenerates/updates /dist files