gui: #2614 fixed: problems with displaying unread messages

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
gui: disable chat pruning by default

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
translations: updated

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
message: move sroting method to SortedMessages

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
misc: add generic sorted_vector

As you can see, my templates are not as good as as they should be.

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
misc: add unit tests for sorted-vector

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
misc: rename sorted_vector to sorted_unique_vector

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>