Implement Pull #3528 from citra: use nvidia graphics automatically on laptops with optimus (with AMD support) (#271)

* Port 3528: use nvidia graphics automatically on laptops with optimus

* Force dedicated AMD Card for switchable Graphics

* Ran clang-format

* core, main.h: Abort on 32Bit ROMs

* main.cpp: Fix Grammar

configure_general.ui: Add UI Option for Themes

config.cpp: Save Theme Settings

Just as a proof that it works

* Removes the use of QKeySequence::Cancel to remove issues while running make

* Corrects characters in a line for travis failure

* Corrects space in a line for travis failure

User pointed out on the Discord server that "nothave" is erroneously concatenated. Added a space to prevent it.

 - Deleted GetStatus() because it wasn't used anywhere outside of Core::System.
 - Fixed design flaw where the message bar status could be set despite the game being stopped.

Optimized messages that were repetitive and added ability for core errors to specify more details optionally.

- Made LoadKernelSystemMode return a pair consisting of a system mode and a result code (Could use review).
- Deleted ErrorOpenGL error code in favor of just having ErrorVideoCore.
- Made dialog messages more clear.
- Compared archive ID in fs_user.cpp to ArchiveIdCode::NCCH as opposed to hex magic.
- Cleaned up some other stuff.