Fixed issue #2222: 'Prune' in the pull dialog does not work

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Add editorconfig-core-c library as submodule

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
TortoiseGitMerge: Add CEditorConfigWrapper class which calls editorconfig

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
Use EditorConfig tabwidth and indentstyle settings

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>