Fix issue #414 Changing the value of an element from negative to positive is...

Fix issue #414 Changing the value of an element from negative to positive is not possible for some specific configuration of brackets

Modify the jasmine default timeout in order to allow for longer end-to-end tests.
Simplify `_addGroupSeparators` and `_onFocusOutAndMouseLeave` by using `this.settings.rawValue` instead of `this.settings.trailingNegative`.

Signed-off-by: Alexandre Bonneau <alexandre.bonneau@linuxfr.eu>