* Swap "Plus" with "Minus" on the controller GUI

Major fix /s

Instead, we make a proper registry class and house it within the main
window, then pass it to whatever needs access to the loaded hotkeys.

This way, we avoid a global variable, and don't need to initialize a
std::map instance before the program can do anything.

* GDBStub works with both Unicorn and Dynarmic now

* Tidy up

Makes code consistent with our style of defaulting special member
functions where applicable.

Added ability to change username & language code in the settings ui. Added IProfile::Get and SET::GetLanguageCode for libnx tests (#851)

Instead of using an unsigned int as a parameter and expecting a user to
always pass in the correct values, we can just convert the enum into an
enum class and use that type as the parameter type instead, which makes
the interface more type safe.

We also get rid of the bookkeeping "NUM_" element in the enum by just
using an unordered map. This function is generally low-frequency in
terms of calls (and I'd hope so, considering otherwise would mean we're
slamming the disk with IO all the time) so I'd consider this acceptable
in this case.

configure_general.ui: Add UI Option for Themes

config.cpp: Save Theme Settings

* Rename verticalLayout_25 to verticalLayout_23.

* Rename almost all classes.

citra-qt: Rename derivative class name