Windows: Add additional logging to setup script to make diagnosing installation failures easier

Example failure (that lacks enough detail to diagnose the problem):

5/8/2019 2:56:47 PM: ---- Start GVFS Install Log ----

2019-05-07 11:19:39.711   Log opened. (Time zone: UTC-07:00)
2019-05-07 11:19:39.711   Setup version: Inno Setup version 5.5.9 (u)
2019-05-07 11:19:39.711   Original Setup EXE: <path to exe>\SetupGVFS.1.0.19074.2.exe
2019-05-07 11:19:39.711   Setup command line: <command line details>
2019-05-07 11:19:39.711   Windows version: 10.0.17763  (NT platform: Yes)
2019-05-07 11:19:39.711   64-bit Windows: Yes
2019-05-07 11:19:39.711   Processor architecture: x64
2019-05-07 11:19:39.711   User privileges: Administrative
2019-05-07 11:19:39.712   64-bit install mode: Yes
2019-05-07 11:19:39.714   Created temporary directory: C:\Users\<user name>\AppData\Local\Temp\is-FOK3Q.tmp
2019-05-07 11:19:39.974   GetConfiguredUpgradeRing: upgrade.ring is slow
2019-05-07 11:19:40.174   IsConfigured(upgrade.feedurl): value is 
2019-05-07 11:19:40.373   SetIfNotConfigured: Set upgrade.feedurl to <feed url>
2019-05-07 11:19:40.553   IsConfigured(upgrade.feedpackagename): value is 
2019-05-07 11:19:40.752   SetIfNotConfigured: Set upgrade.feedpackagename to <feedpackagename>
2019-05-07 11:19:49.756   StopService: stopping: GVFS.Service


---- End GVFS Install Log ----

5/8/2019 2:56:47 PM: Error: Failed to install GVFS 

The issue names no file or test; start by locating the Windows setup script that produces the shown GVFS Install Log and trace the failure path ending in “Failed to install GVFS.” Done means the installer records enough additional context to diagnose installation failures, with the relevant setup validation or installer checks passing.