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)
Merge pull request #10 from stefanopanella/master

Make Windows Build Machine from public URLs (step 1)
[do_build.sh] Remove optional steps...

... to minimize build breakage.
- nilfvm does nothing.
- copy requires extra configuration lines that are not yet documented, or it tries to copy stuff to /master, which breaks the build for most users.
- extra_pkgs can be replaced by just manually building the extra packages needed, which widely vary between users anyway.
- packages_tree also requires extra configuration. That step is probably not needed for most users either.
Merge pull request #11 from jean-edouard/master

[do_build.sh] Remove optional steps...
Remove Windows Quality Tools step
Adding inf2cat to Win7DDK path
use INF2CAT command from win7DDK path
Use public URL for VS2012P
Use Public URL for VS2102 Premium
Fix VS2012 Pro URL
Default WinDDK is now 7.1
WDK 7.1 signtool.exe lives in a different place
Stop Installing WDK 6001
Remove WDK 6001 installer script
Merge pull request #12 from stefanopanella/master

Make Windows Build Machine from public URLs (step 2)
Give output when the script is done
Merge pull request #13 from dotdashnotdot/master

Give output when the script is done so that if run from a run registry key the user can see something on successful completion.
Make Windows Build Machine from public URLs (step 3)

Put  8.0 signtool in the path
Install  WinDDK 7.1 from public ISO
Install 7zip and download WinDDK 7.1 public ISO
Allow Win8SDK to download sdksetup.exe
Use public URL for SDKWin8
Change WDKWin8 URL into two public URLs
Remove MSM URL and step
Delete install-msms.ps1
Make install-wdk-win8.ps1 download exe and msi
Merge pull request #14 from stefanopanella/master

Make Windows Build Machine from public URLs (step 3)
Rewrite mkbuildmachine for simplicity and robustness.

Status: I have rebased this a few times to incorporate feedback. Currently
all feedback is implemented apart from the request to keep the built in reboot
logic which has been discussed, so I think this is ready to merge.

The previous version of this code would only work on a clean machine, lacked
error checking (e.g. the exit codes of installers were not inspected and
in fact some were failing, albeit harmlessly) and had some sophisticated
logic to check error codes. We also have some separate code in
windows/winbuild-prepare.ps1 to verify some aspects of the build machine are
suitable.

All the actual install logic here is based on the previous version, but
in addition there are checks that each step is necessary before running it.
This allows a nice simple control flow where you log in to a windows machine,
run this script, and watch it install things. You can re-run any steps
that were problematic and reboot when you like. After typically a problem
or two you'll run this script and find it thinks everything is fine. We'll
also run the script in read-only mode (without the -apply) flag before
each XT windows build.

The test code is pretty primitive, and I suggest we plan to extend it
each time we get a problem with a windows build machine, until the
test code is fairly reliable.

I'm open to the possibility of adding reboot logic and the run hooks
back in, but frankly I don't think I'd use or recommend it. Windows
build machine setup may just be too complex to happen automatically
with a complex state machine and no troubles.

There is also a mechanism here for secure hashing downloads and the
windows/PackageLibrary.psm1 file includes secure hashes of (nearly) everything
to ensure integrity and allow safe reuse of material that is alread
available.

Many of the tests and the download code are by aikidoka used with
permission.