[Patch] Blame: Fix incorrect parent windows for the progress dialog

[Denis Kovalchuk]

Hi!

I've noticed that the parent window for the "CProgressDlg" [1] may be set
incorrectly when using the Blame command.

The "Blame" [2] class is used in the following cases:
1. The "Blame..." command in the Windows Explorer context menu.
2. The "Blame..." command in the "Log Messages" dialog context menu.
3. The "Blame..." command in the "Repository Browser" dialog context menu.

In all these cases, the "Blame" class uses GetExplorerHwnd() [3] as the parent
window for the progress dialog. This is incorrect for cases 2 and 3, because
the parent windows are the dialogs.

For comparison, the "Show changes" command behaves correctly:
1. It uses GetExplorerHwnd() [4] in the case of the Windows Explorer context
menu.
2. It uses the dialog's m_hWnd [5] in the case of the "Log Messages" context
menu.

For example, this causes some problems with disabling the parent
window, when TortoiseProc.exe is called with the /hwnd parameter.

Here is a patch in attachments.

[1] https://sourceforge.net/p/tortoisesvn/code/29768/tree/trunk/src/Utils/MiscUI/ProgressDlg.h#l30
[2] https://sourceforge.net/p/tortoisesvn/code/29768/tree/trunk/src/TortoiseProc/Blame.h#l32
[3] https://sourceforge.net/p/tortoisesvn/code/29768/tree/trunk/src/TortoiseProc/Blame.cpp#l217
[4] https://sourceforge.net/p/tortoisesvn/code/29768/tree/trunk/src/TortoiseProc/Commands/DiffCommand.cpp#l36
[5] https://sourceforge.net/p/tortoisesvn/code/29768/tree/trunk/src/TortoiseProc/LogDialog/LogDlg.cpp#l3000