core: #2758 fixed: crash during 0.6.6 configuration import

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
plugin: fix look of widget on Qt5

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
x11: move x11tools to separate directory

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
win: use RAII for WSA

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
configuration: replace config_file_ptr with config_file

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

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
configuration: remove more unused methods

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

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
fixup! configuration: remove more unused methods

Signed-off-by: Rafał Malinowski <rafal.przemyslaw.malinowski@gmail.com>
plugin: use QSettings intead of PlainConfigFile

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

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