Name 'visualc_net' invokes old names for Visual Studio
(Visual Studio .NET 2002 or 2003), which has no relation to content of
this subdirectory.
Also, by renaming this directory we mitigate chance, that during
merge-in from svn/trunk git will automatically inject some values from
from upstream, incompatible version of solution files. By sheer
luck this might happen without causing a conflict. Never happened so
far, but there's no point in risking it.
