Removed outdated InnoSetup installer and renamed WixInstaller directory into the canonical "installer"

--HG--
rename : WixInstaller/Makefile => installer/Makefile
rename : WixInstaller/adblockplusie.wxs => installer/adblockplusie.wxs
rename : WixInstaller/bho_registry_value.wxi => installer/bho_registry_value.wxi
rename : WixInstaller/custom_WixUI_InstallDir.wxs => installer/custom_WixUI_InstallDir.wxs
rename : WixInstaller/dll_class.wxi => installer/dll_class.wxi
rename : WixInstaller/en-us.wxl => installer/en-us.wxl
rename : WixInstaller/index.html => installer/index.html
Updated to current libadblockplus revision