Add onClientChatboxLayoutChange event

[XJMLN]

Event: onClientChatboxLayoutChange
Description:
Triggered when the client changes any settings related to the chatbox layout.

Parameters:
chatboxLayout: A table containing all CVars values related to the chatbox settings.

Usage Example:

addEventHandler("onClientChatboxLayoutChange", root,
    function(chatboxLayout)
          iprint(chatboxLayout)
    end
)

Resolves #696

[Lpsd]

Seems good to me, just left one comment.

[botder]

SString constructor can do printf formatting.

[botder]

Suggested change

	void SetChatLayoutChanged(bool changed) { m_bChatLayoutChanged = changed; };
	bool GetChatLayoutChanged() const { return m_bChatLayoutChanged; };
	void SetChatLayoutChanged(bool changed) { m_bChatLayoutChanged = changed; }
	bool GetChatLayoutChanged() const { return m_bChatLayoutChanged; }

[botder]

The header belongs in Client/sdk/core if you want to interface between core and deathmatch.

[botder]

You could use an array of struct for g_chatboxLayoutCVars, and store the type of value next to the cvar name. For example:

enum class DummyType {
    STRING,
    BOOLEAN,
    FLOAT1,
    FLOAT2,
    FLOAT4,
};

struct Dummy {
    const char* name;
    DummyType   type;
};