Add --core/--script/--pipe options to the wscript.

These can be used to enable/disable individual VS components.
Also install example plugins.
Only print configuration values after they have been sanitized.
Document new configure options in INSTALL.
Merge branch 'master' into cuda

Conflicts:
	wscript
Add back CUDA debug options to wscript.

Don't know what the bloody hell happened to them in the first place.