Custom window/application icon support

This is the last feature from RPG_RT.exe PE resources that could be provided in Player when games use a custom icon in RPG_RT.exe. This icon applies for the desktop status bar / alt+tab switcher and Window title on certain desktops.

Currently, EasyRPG logo as icon is displayed there as it is supported by SDL in a cross-platform way, but it could be nice for games that customize the main ICON resource in RPG_RT.exe to replace the Player default with it for not known rm2k/3 default icon versions. Because PE reader is used already for custom splash and custom fonts, this could complete the custom resource support.

For games not using RPG_RT.exe at all (thinking on future editor feature), a setting to provide the icon, and/or a default path looking for some .ico/.png could do the trick.

[Br4ssman]

In RPG_RT it can change that name to Game or whatever .exe, but in the past when an user do this, in the title window bar the icon was blank and "Unknown" text replace the title of the project, but not now with RM 2k3 1.12a.

For EasyRPG would be this in a "Picture" folder or a new "icon / ico " folder?

Thank you.