Use proper font for View>Use Default Font menu item

[GreyMerlin]

Use proper font for View>Use Default Font menu item

Symptom:

Use of the View > Use Default Font menu selection always
sets the Directory Tree window to the 12-point Courier New font,
which is not the default font for that window.

Discussion:

WinMerge has an Options::Font structure that maintains an
in-memory copy of 'actual' and 'default' values for the font of
each of the Directory Tree and File View windows. This structure
is populated at program initialization by procedure SetDefaults()
in file Src/OptionFont.cpp. The 'default' values are generated by
this procedure, the 'actual' values are loaded from the Registry.

The existing code only queries the system for the default fixed-
size font (via the default MIME codepage) and then uses this font
as the 'default' value for the Options::Font structure for both
Directory and File windows. This value is typically Courier New.

However, WinMerge actually uses the Menu font as the actual Directory
window font if no other font is marked as 'Specified' in the
Registry. The default Menu font (for English, since Windows 7) is
Segoe UI. But this use of Segoe UI has never been reflected in the
Options::Font structure, nor in the Registry.

By having the proper information in the 'default' value in the
Options::Font structure, the View > Use Default Font menu
selection now works correctly.

Implementation:

• The procedure SetDefaults() is modified to additionally capture
  the system-wide Menu font information via SystemParametersInfo()
  to be used for the Directory Tree window, while continuing to use the
  codepage MIME font for the File View window.

• A "helper" function is added: InitializeLogFont(). It should only
  be used within Src/OptionFont.cpp. It is documented by comment in
  the Src/OptionFont.h file.

• The information in the Registry for the Options::Font structure
  now always reflects the values of the in-memory structure, and
  the values being used by the windows themselves.

Incidental changes:

• Numerous added or modified comments in Src/OptionFont.cpp
• Reordering of all Registry related code to be in the canonical
  order implied by the layout of the LOGFONT structure itself.
• Explicitly cast the three boolean values (Italic, Underline,
  Strikeout) to boolean to invoke the properly typed Options::Font
  procedures (InitOption(), SaveOption())
• Remove two unnecessary String() function references relating to
  font in files Src/DirView.cpp and Src/MergeEditView.cpp

[GreyMerlin]

Sorry about the four "Merge ..." commits. They are harmless and have no impact on the code; they are redundant with your "Merge ..." commits.

[sdottaka]

Thank you!

Sorry about the four "Merge ..." commits. They are harmless and have no impact on the code; they are redundant with your "Merge ..." commits.

There is no problem at all.

[GreyMerlin]

Thank You !!