dynamic and static c-ares libraries in debug and release flavours.

Additionally each of the three sample programs is built against
each of the four possible c-ares libraries, generating all this
a total number of 12 executables and 4 libraries.

don't ignore these subdirs, they must be removed first

ahost are ws2_32.lib and advapi32.lib

c-ares library. It is just a convinience source code helper function
for use in example programs adig.c and ahost.c