Move to .NET 4.5

.NET 3.5 on Windows 8 and above must be explicitly enabled. Because it
seems likely that people running Vista or 7 already have .NET 4.5
installed this should result in a smoother user experience.
Enable default manifest

I see no reason to stray from the defaults if I don't know what this does.
Set neutral language to English
Further .Net version updates?
Set project startup
Second part of default language -- REBASE when merging into master

It turns out that when you change the neutral language, the "(Default)"
localization is used if the system language matches it, even if there is
an explicit localization for the system language.

TL;DR the strings are no longer blank on English systems, and now as
intended English is used in the absence of localization.
Add machine-translated French localization
Add... empty property group?

Why did Visual Studio put this here? What does it do?
Hide main window

Even though the window was not on top it was still being shown.
Replace single-line event handler function with lambda
Avoid printing multiple file not found error messages

Application.Exit() enqueues an exit message; it does not immediately exit.
Allow running the application from outside its directory

This is required for being run at startup.
Add command-line switches
Add preferences window

Currently only changes startup options
Set application icon
Add forgotten preferences window files REBASE
Remove accidentally added line
Remove stale PID file on startup