Remove the default ./libs search directory

When searching for the ETO assembly we would look in the ./libs before
any paths passed through the path_list argurement. We remove the ./libs
from the search path list
Refactored use_cs code

Since attribute of ConfigSet are list then we should check the size
instead to see if we have items in it.
Only create one task per target

the read_csshlib would create multiple task if you had to reference
the library on multiple project tree. A check was added to see if the
task_gen already existed for this library, and if so, then don't
create a new one.
Simplified the import_resources function

A namespace can be include with your embedded resource.
remove all keyword params from the function, only a list of
resource path can be used to specify the resource to be imported
External assembly are copied into the build directory

A copy of all external assembly are copied into the build directory.
for use when debugging your codes.