widl: Make constdef and externdef take a declarator instead of an ident so that functions and arrays can be defined using the statements.

Fix applying calling convention to function type.

Use an attribute to store the const qualifier for the pointer and type.

Allow multiple type-qualifiers to be applied to a type by adding a 
declaration-specifier rule that encompasses type-qualifiers and types.

wgl: We were already advertising GL_EXT_framebuffer_sRGB but not the corresponding WGL_FRAMEBUFFER_SRGB_CAPABLE_EXT.

Otherwise, a paragraph with multiple rows might fail to make the
scrollbar appear when displaying text.

As text is inserted, the cursor is moved to the end, and then back to
offset 0. A reordering of operations prevents a WM_NOTIFY from being
sent on cursor being moved to the end, and another by being moved
back to the beginning. If the cursor was not at offset 0, then
exactly one WM_NOTIFY must be sent, for the movement from previous
position to the beginning.  With tests to prove this change and the
previous one (modify flag should be off on WM_SETTEXT-caused
WM_NOTIFY).