Code Cleanup - Member variables not initialized in GdiEngine's constructor

[dlong11]

Minor Code cleanup

In src/renderer/gdi/state.cpp
GdiEngine's constructor is not initializing all of it's member variables.

_isTrueTypeFont
_fontCodepage
_tmFontMetrics
_coordFontLast
_psInvalidData

In Debug only
_debugWindow
_debugContext

As far as I can tell, none of the above variables are used before being initialized (in the normal code path). Most of these get set in UpdateFont and _CreateDebugWindow. It might make sense to make a pass and initialize these in the header with default values. Some members are correctly being set to a default value in the constructor, but it might be better for maintainability to remove those and initialize them in the header also.

[binarycrusader]

Spot-checked a few, so marking as confirmed.

Two important guidelines to keep in mind for whomever wishes to resolve this:

C.48: Prefer in-class initializers to member initializers in constructors for constant initializers
C.45: Don’t define a default constructor that only initializes data members; use in-class member initializers instead