Added support for prebuilt TAP-drivers. Automated embedding manifests.

Added support for prebuilt TAP-drivers. Automated embedding manifests.

Removed win/make_dist.py's dependency on TAP-driver and tapinstall.exe building.
Also added manifest embedding commands to win/make_dist.py. To avoid duplicate
code moved the "build_vc" method from win/build.py to win/wb.py and renamed it
"run_in_vs_shell".

Signed-off-by: Samuli Seppänen <samuli@openvpn.net>
Acked-by: James Yonan <james@openvpn.net>
Signed-off-by: David Sommerseth <davids@redhat.com>