Make installer components buildable with VS express

[jng]

The current installer components are not buildable via VS express due to the following:

• Installer.sln is a solution of Wix/C++ projects. VS express can't build heterogeneous solution files.
• The apache custom action uses MFC, which is not included (and thus not buildable) in VC express.
• VS express doesn't support bootstrapper packages AFAIK

This ticket proposes the following be done to address this:

• Split Installer.sln into separate wix and custom action solutions. Modify build.bat to build these solutions separately.
• Rewrite the apache custom action library using a non-MFC approach
• Ditch the existing bootstrapper and tweak the NSIS installer to include logic that determines whether to launch a vc_redist installation before the main msi installer is executed. In effect the NSIS installer *becomes* the bootstrapper.

[jng]

Fixed r5409