Build 4088

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r4088 | hendricks266 | 2013-10-07 03:06:09 -0700 (Mon, 07 Oct 2013) | 1 line

Fix OpenGL under SDL && Windows. (Almost. SDL 1.2 works fine, but SDL2 has an unresolved problem where OpenGL screen updates flicker over a black background.)
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r4087 | hendricks266 | 2013-10-07 03:05:54 -0700 (Mon, 07 Oct 2013) | 3 lines

Fix "warning: iteration 1461 invokes undefined behavior [-Waggressive-loop-optimizations]" in initkpeg() by promoting the variables in question to int64_t.

NOTE TO TEAM MEMBERS: Please review this, as I am not sure what is actually intended here.
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r4086 | hendricks266 | 2013-10-07 03:05:41 -0700 (Mon, 07 Oct 2013) | 3 lines

Windows startup window tweaks:
- Don't print osd.szCSDVersion when it is empty, preventing an extra space between the OS name and version number. (An example of what this field holds is "Service Pack 1".)
- Under SDL, allow the "console" edit field to repaint after "OK" is clicked. Important when a long def file is loading.
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r4085 | hendricks266 | 2013-10-07 03:05:24 -0700 (Mon, 07 Oct 2013) | 3 lines

Allow wm_msgbox() to use SDL_ShowSimpleMessageBox() under SDL2.

Unfortunately, SDL2 does not (yet?) provide a Yes/No box for wm_ynbox().
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r4084 | hendricks266 | 2013-10-07 03:05:03 -0700 (Mon, 07 Oct 2013) | 1 line

Split the handling of audio based on RENDERTYPE into a new variable named MIXERTYPE, allowing Windows builds to use SDL for input and rendering (RENDERTYPE=SDL) while using DirectSound and Windows' MIDI interface (MIXERTYPE=WIN [current default]) so that EMIDI works.
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