Remove hardcoded MAXPRINTMSG buffer.

On Surface Pro 3 the GL_EXTENSION string is larger than 4096 bytes, which ends up overflowing this buffer. Allocate the buffer dynamically instead.
Set PreserveSbr so incremental builds work.
Add application manifest.

There are two settings here:
- Turn off automatic DPI scaling for legacy applications. See http://msdn.microsoft.com/en-us/library/windows/desktop/dn469266%28v=vs.85%29.aspx#declaring_dpi_awareness for more details.
- Declare ourselves compatible with every version of Windows up through Win8.1.