Initial commit of XsdDoc, an XML schema documentation plug-in for SHFB
Update build logic to reflect move to TFS

Take care of the following items:

- Add custom build task to remove TFS bindings
- Remove the .svn references from the build
Update TFS bindings in Setup.sln
Use an official XML schema namespace

Replace the temporary URI

    "http://tempuri.org/XMLSchema.xsd"

by this one

    "http://schemas.xsddoc.codeplex.com/schemaDoc/2009/3"
Set version number to 1.8.0.1
Exclude maximum version from being upgraded by setup
Fix homepage in setup
Add option 'IncludeLinkUriInKeywordK'

Add option 'IncludeLinkUriInKeywordK' that allows XML entity links such
as

    http://schemas.example.org#E/myElement/@myAttribute

to be included in the K keyword index.
Fix help file version
Fix bug that causes 'IncludeLinkUriInKeywordK' to not being saved
Use MSBuild properties to specify path and version for help file

Also add a GetFileVersion task that allows extracting the version number
during build. Use it to enforce that the help file always has the same
version number as XsdDocumentation.dll.
Fix topic id generation to create stable ids

Use the same algorithm as Sandcastle. That is, generate an MD5 hash of
the regular link URI and convert the result to a GUID. This keeps topic
ids stable over multiple builds.

Also, make it possible to link to overview topics such as the schema set
itself.
Centralize error handling of unexpected case labels

Replace ArgumentOutOfRangeException in default clause of switch
statements by calls to ExceptionBuilder.UnhandledCaseLabel.
Fix bug in schema that makes the obsolete element required
Fix RemoveTfsBindings to preserve the encoding of the solution file
Move all folders into a new folder 'Main' to allow easier branching
Fix bug so that we can link to the empty namespace
Fix structure of the plug-in project
Externalize strings in plug-in project
Remove links to XsdDocumentation.xsd and AnnotationTranform.xslt

Change setup so that theses files are directly picked up from the
etc\Schemas