Make desktop shortcut optional on install

Especially useful when upgrading
FileViewer: hotkeys for jumping to next / previous change. Default binding to "None".
Add default configuration for meld diff tool.
Ignore not existed ssh files
Check only once per file if it exists.
Prevent argumen exception when _workingdir is not a directory.
Check if url is a directory.
Ask for remote branch if not specified.
Merge branch 'release/2.47'

Conflicts:
	GitCommands/Git/GitModule.cs
Merge pull request #1981 from DanRigby/DesktopShortcutWixOption

Make desktop shortcut optional on install
Merge pull request #1990 from JoanCharmant/master

FileViewer: hotkeys for jumping to next / previous change. Default binding to "None"
Default hotkeys as per PR #1990 comment.
Merge pull request #1992 from JoanCharmant/jc/meld

Add default configuration for meld diff tool.