[AD] 3 minor suggestions about our cmake build

[Elias Pschernig <elias.pschernig@xxxxxxxxxx>]

1. static/debug examples?

Right now, it seems a bit arbitrary what examples I get if I build
multiple library versions at once. I think we also should compile
multiple versions of the examples in that case, and always name them
accordingly, so:

ex_blend
ex_blend-debug
ex_blend-profile
ex_blend-static
ex_blend-static-debug
ex_blend-static-profile

2. Why build twice by default?

I think only the shared release build should be built by default, having
everything compiled twice by cmake as is done right now likely will look
strange to new users. (And everyone who does serious development will
have to run cmake-gui and check the "debug" option, so they certainly
can do that for the much less likely case that they also want the static
library.)

3. Why the GRADE_* variables?

Having finally read the cmake documentation, it seems they always assume
that there is only one build type (CMAKE_BUILD_TYPE =
Debug/Release/RelWithDebInfo/...) per output build directory, and
especially when talking about VC they seem to discourage a solution like
our current GRADE_DEBUG/GRADE_STANDARD. Should we follow them or keep
going with our custom GRADE_ variables?

-- 
Elias Pschernig <elias@xxxxxxxxxx>