shell32: Fix the logic in Control_LoadApplet determining when to use CPL_INQUIRE and when to use CPL_NEWINQUIRE.

Previously, the code would fail to get the name of an applet that didn't 
return an icon for CPL_NEWINQUIRE and didn't return set either idName or 
idIcon to a non-zero value for CPL_INQUIRE.

Fix this by sending CPL_INQUIRE first and loading any strings or icon 
specified and then only fall back to CPL_NEWINQUIRE if any of the 
required members were zero (i.e. CPL_DYNAMIC_RES) and then only fill in 
these fields.

As some Mesa developers pointed out, the GL_ARB_vertex_program grammar
does not allow an immediate value as source argument in ARL. Most
compilers accept it, but since it is not the purpose of the test
program to test for this replace it with a proper constant.

Changing the texture unit when binding a surface for loading can break
the state manager in the way that it changes the currently active
texture unit while it is setting up a texture that has to be loaded.
Instead find out the current unit to dirtify the correct sampler.

Fix RegSetValueA/W to return ERROR_INVALID_PARAMETER if NULL data is 
passed in.