Assorted spelling fixes.
winmm: Fix two error messages to not point users to a MIDI Mapper configuration applet we don't have.
cmd: Mention that the % must be doubled for FOR variables in batch files.

Also standardize on the 'Usage:' prefix for usage messages.
cmd: Standardize the references to directories in the builtin command usage messages.
gdi32/tests: Fix copy&paste issues related to gmBlackBoxY.
gdi32: Fix empty glyph handling in the dib driver.
gdi32: Return fake BBox when requesting empty glyph metrics.
winemac: Remove a too-early attempt to set the process's Dock icon.
winemac: Reapply display modes when switching back to app after "escaping" with Command-Tab.

The Mac driver captures the displays when the program changes the display
mode.  If the user types Command-Tab to switch away, it resets the displays
to their original modes and releases them.  However, if they switched back,
it didn't restore the mode to what the program had set, so the program often
showed the game window in a corner of the screen with the top behind the Mac
menu bar.
riched20: Continue interpreting data as UTF-8 after the first chunk boundary.
tests: Use the explicit LoadLibraryA function.
qedit/tests: Use the W version of FindResource().
iphlpapi/tests: Use the W form of CreateEvent().
msvcr90/tests: Use the W form of CreateEvent().
windowscodecs/tests: Use the W version of GetObject().
tests: Readying some tests for the compilation with -D__WINESRC__.
tests: Compile the tests by default with -D__WINESRC__.
d3d8: Don't mask out internal wined3d usage flags in surface_init().
d3d9: Don't mask out internal wined3d usage flags in surface_init().
wined3d: Send vertex buffer binding updates through the command stream.