libgit2 clone: Show ref update information after fetch

Signed-off-by: Frank Li <lznuaa@gmail.com>
Signed-off-by: Sven Strickroth <email@cs-ware.de>
libgit2: Enable fetch function

but update tip fails when run like "git fetch url branch"

Signed-off-by: Frank Li <lznuaa@gmail.com>
Signed-off-by: Sven Strickroth <email@cs-ware.de>
GitProgressDlg: Add context menu support to open file or show log

Signed-off-by: Frank Li <lznuaa@gmail.com>
Signed-off-by: Sven Strickroth <email@cs-ware.de>
Dropped unused code

Signed-off-by: Sven Strickroth <email@cs-ware.de>
Fixed a warning

Signed-off-by: Sven Strickroth <email@cs-ware.de>