Extend the VersionInfo class to support info strings

This is a major rewrite of VersionInfo (now called FileVersionInfo)
that loads the version info block once (at construction), and then
allows repeated querying of the loaded data, without have to reload.

This new FileVersionInfo class also supports querying file info strings
which we'll use soon for checking whether or our hook DLL is installed.
Remove done @todo comment
Add check for hook installation

This commit includes the basic UI logic, but does not yet have a valid
test for installation, nor an installation mechanism (coming soon).