It seemed impossible to SELECT an item, however, when right clicking, the CURRENT item is set to the appropriate cell, this commit makes the view use thta cell instead of the first selected one.
This makes it possible to use enums as the config type.
Default values are now clearer and there's no need for casts
when calling Config::Get/Set anymore.
In order to add support for enums, the common code was updated to
handle enums by using the underlying type when loading/saving settings.
A copy constructor is also provided for conversions from
`ConfigInfo<Enum>` to `ConfigInfo<underlying_type<Enum>>`
so that enum settings can still easily work with code that doesn't care
about the actual enum values (like Graphics{Choice,Radio} in DolphinQt2
which only treat the setting as an integer).
This excludes the second argument from template deduction.
Otherwise, it is required to manually cast the second argument to
the ConfigInfo type (because implicit conversions won't work).
e.g. to set the value for a ConfigInfo<std::string> from a string
literal, you'd need a ugly `std::string("yourstring")`.
Avoids needing to iterate and append the characters in one case. This also
alters the function to not need to construct a temporary std::string
(QString's toUtf8() is sufficient, as QByteArray exposes iterators).
toStdString() is equivalent to retrieving the QString's underlying
QByteArray via calling QString's .toUtf8 member function and then
calling .toStdString() on the result of it (discarding the QByteArray
afterwords), so this just trims off an unnecessary step in the process.
This is also somewhat more indicative of the conversions going on:
toStdString() converts the underlying character sequence of a
QString to UTF-8, not strict ASCII, so we're really using a superset of
ASCII.
