Removed unused class Future
Tweaked DllImport CharSets
Turned immutable Comparers into Singletons
Improved ITask and ITaskHandler XML comments
CopyDirectory: Remove Hidden file attribute in addition to ReadOnly attribute

Samba shares implicitly mark dot files as Hidden, potentially causing problems when copying/overwriting
Extracted LanguageSet.KnownLanguages to Languages.AllKnown

Removing this from LanguageSet avoids unnecessary execution of the static constructor when we want to create a LanguageSet but do not need a list of all languages.
Added FileUtils.IsUnifxFS()
Tweaked DownloadFile
Moved ArgumentUtils from Cli to Utils namespace
Common.WinForms: Allow modification of FilteredTreeView.CheckedEntries
WindowsUtils: Moved file-system related methods into seperate file
FileUtils: Added .Read/WriteExtendedMetadata()
Tweaked .gitignore/cleanup
Incremented version number
FileUtils: Removed unused GetDirectories()
FileUtils.Walk(): Added followDirSymlinks parameter
Removed ineffective synchronization lock on CliTaskHandler.RunTask()
Task.CopyDirectory: Wrap ArgumentException from FileSystemInfo.Attributes_set in UnauthorizedAccessException
Task.CopyDirectory: Copy Unix symlinks
Extracted Windows 7 taskbar code from WindowsUtils to new WindowsTaskbar

This avoids the overhead of initializing the taskbar COM objects in the WindowsUtils static constructor when no GUI is used.