TortoiseGitMerge: Add Status label in FindDlg

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
TortoiseGitMerge: Move match count message to FindDlg status bar

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
TortoiseGitMerge: Show find status Not found, top reached, bottom reached

Signed-off-by: Sup Yut Sum <ch3cooli@gmail.com>
TortoiseGitMerge: Add Search Up direction

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