i18n translation pointer names

In order to have a consistent code-base in PPSSPP, please use these pointer names when you require a translated string somewhere:

Pointer name	Translation category name
a	Audio
co	Controls
cr	PSPCredits
cw	CwCheats
des	DesktopUI
dev	Developer
di	Dialog
err	Error
ga	Game
gr	Graphics
iz	InstallZip
km	KeyMapping
mc	MappableControls
mm	MainMenu
ms	MainSettings
n	Networking
pa	Pause
ps	PostShaders
ri	RemoteISO
rp	Reporting
sa	Savedata
sc	Screen
si	SysInfo
st	Store
sy	System
u	Upgrade

Example syntax in code:

I18NCategory *ps = GetI18NCategory("PostShaders");