Make Windows Build Machine from public URLs (step 1)

This change is the first result of the effort to install
all tools needed to build OpenXT windows components using
public URLs.

- Update Helper URL
- Remove libre branch tag
- Update Cygwin URL
- Update nsis URL (2.46 now) and Check we are using >= than 2.23
- Update capicom URL
- Add MSMSrc patch
- update dotNetFx45_Full_setup.exe URL
- Update SQLSCE32 and SQLSCE64 URLs
- Update VS2012U4 URL
- Update Wix URL

Wix URL is now hardcoded in install-wix.ps1 (This is needed because
if we put this URL in the config file the XML parser fails because
of the &, so embedding the URL here is a workaround for the problem)