ShellExtensionSettingsPage: add simple preview for context menu items
minor: do not show Repository hosts when switching between repo and dashboard
minor: add ellipsis
revision grid context menu: copy to clipboard: move "Commit hash" to top
revision grid context menu: copy to clipboard: show whats going to be copied behind menu item
supporting -exec, make it simpler
Apply ellipsis rules for menu items
Merge pull request #1780 from feinstaub/topic_minor_GUI_fixes

minor GUI fixes
Submodule GitExtensionsDoc updated.

Submodule GitExtensionsDoc:
    < 439e4cb - add section about re-taggin
Obtain candidate list in main thread to avoid cross thread access to gui component. Closes #1783.
Return all items.
ConfigFile.GetConfigSections() transformed to property
Heads renamed to Refs when appropriate
Partially revert "ConfigFile.GetConfigSections() transformed to property"
DateTime format moved to function GitCommandHelpers.GetFullDateString(). Refs #1782
Removed dot from message generated for submodules
remove nuget restore packages for non windows for now
Merge pull request #1786 from fraga/fixMoreMonoBuild

remove nuget restore packages for non windows for now
Separate methods for nullable enums.
ConfigFileParser - handles comments, escaped values, quoted values.

TODO: recreate comments when saving config file.