Installer update for VS 2012

[jng]

• Include VS2012 vcredist installers
• Update InstallerPreReq_VS2010.sln to VS2012. Keep the wix sln at VS2010 format as we can still build this through VS2012 via command-line
• Remove Windows XP/2003 support (VC++ 2012 drops XP support and we're not building with XP re-targeting)
  • Remove iis_actions project as IIS7 is the minimum version as a result of dropping XP/2003 support
  • Remove IIS6 related sections from wix installer
• There are two redundant sets of mapagent binaries. Only one is being used depending on whether it is the Apache/IIS configuration. We should tweak the configurations so that the same set of mapagent binaries are used, shaving off some installer space.
• Update the FastCGI notice screen. Dropping XP/2003 means no external download is required.

[crispinatime]

Can you also please review the "FastCGI Required" screen for IIS installs.

The current screen references a download from IIS.net but I believe that this is only for Windows 2003 (now unsupported by VS2012 / MGOS 2.6+). The warning message should instead reference the CGI components of IIS as part of the Windows Features and Services configuration (the terminology may have changed from Windows 2008 to 2012 servers)

[jng]

Good call