Fix broken Silverlight builds.

Silverlight doesn't have a Thread.Abort that takes an argument, which thread.interrupt_main requires. It's unlikely interrupt_main will be useful on Silverlight, so it's just def'd out.
Update CreateRelease.bat to generate files with version numbers.
Update standard library to match CPython 2.7.
Update MSI version to 2.7.1
Fix CP #30438: Display the correct licence, copyright, and credits in the IronPython shell.
Merge branch 'ipy-2.7-maint' of github.com:jdhardy/ironpython into ipy-2.7-maint
Merge branch 'ipy-2.7-maint' of github.com:IronLanguages/main into ipy-2.7-maint
Add some missed changes from rchandrashekara's patches.

Whoops.
Disable installation of IronPython Tools for Visual Studio by default.

The new Python Tools (http://pytools.codeplex.com) are much better and can't be installed if the IronPython tools are installed.
Make sure all versions 2.7.1 (Beta 1) as appropriate.
Make sys.version_info a namedtuple-alike and update version info. Fixes #30312.
Fix CP #30386.

Set _itemTypes were not properly copied over when a set was initialized with a union operation.
Item 28776 added a check for IRONPYTHONINSPECT environment variable before and after execution
Merge branch 'ipy-2.7-maint' of git://github.com/fdanny/main into ipy-2.7-maint
#30447 added a __format__ method to the datetime module
#23765 change the Equals method to check if the type is either  date or datetime
Merge branch 'ipy-2.7-maint' of https://github.com/fdanny/main into ipy-2.7-maint
Merge branch 'ipy-2.7-maint' of git://github.com/fdanny/main into ipy-2.7-maint
Add a Makefile for Unix systems
Update version info for 2.7.1 Beta 2