makefiles: add a notest target

[Maarten Lankhorst]

Hi Lei,

Lei Zhang schreef:
> Hi,
>
> This patch adds a notest target to build everything but the dll unit
> tests and winetest. This cuts down build time by 25%.
>   
Julliard will never accept such patch. In the hacks.git tree there is a
patch I did that has a configuration time option for it. It would be
cleaner if you used something like 'make SKIPTESTS=1'. I doubt that
alexandre would ever accept any patch that would disable building tests,
though.

Cheers,
Maarten.