Core: Remove some unused functions and types

Rename git submodules, so they are more easily accessible from external tools

EmuWindow: Clip mouse input coordinates to emulated screen dimensions.

If the mouse position for a mouse move/drag would take it outside the emulated screen dimensions, clip the coordinates to
the emulated screen dimensions.
Qt and GLFW will report negative coordinates for mouse positions to the left, or above citra window. Added restriction
to mouse coordinates passed to touchmoved by Qt/GLFW to be greater or equal to zero.

Fix emulation state resetting to support multiple emulation sessions

VideoCore: Remove a superfluous auto variable declaration in debug_utils

ConfigMem: Remove duplicate retail bit

Services/Loader: Use more sensible log formats for certain functions along with more info being logged.

along with more info being logged.

ptm_sysm: Add static specifier to IsLegacyPowerOff

dyncom: Remove more unused/unnecessary code

Gets rid of a sizeable amount of stuff in armdefs.

Add "or any later version" qualifier to the GPLv2 statement in the readme

dyncom: Remove unused/unnecessary VFP cruft

Silence some -Wsign-compare warnings.