Extend DiffTool, MergeTool, EditTool, and ShowTool to support
one or more files in each tool.

Avoid the inconvenience of having to close the drop-down list manually after checking out a branch.

...and format...

Using the workspace file as "merged" allows for the file to be edited in-place for the merge.

…l deletion.

…r from the QProcess constructor for DiffTool.cpp, EditTool.cpp, and MergeTool.cpp so the external tool process lifetimes are not in anyway tied to gittup's lifetime. This simulates QProcess::startDetached() behavior.

…r from the QProcess constructor for DiffTool.cpp, EditTool.cpp, and MergeTool.cpp so the external tool process lifetimes are not in anyway tied to gittup's lifetime. This simulates QProcess::startDetached() behavior.

…eration.

When a directory is selected, all files within it, recursively, are added to the list of 
files selected.  This is not really what the user intends (i.e. if the files are displayed 
as a tree and the user selects from the first to the last, the user really only wants to 
interact with the selected files, not all those in any selected directory).  

Introduce the AccumRepoFiles class to keep track of files actually selected by the user 
as well as those under any selected directory and provide a way to get either list 
individually or both file lists together.

3c92cc0 ("Adds "Hide Untracked Files" option to DoubleTreeWidget cogwheel context menu", 2023-07-02) pvacatel
a80ffed ("Fixes code format according to clang-format", 2023-07-03) pvacatel
b202f1a ("Reverts format changes to test/Settings.cpp", 2023-07-04) pablov
0a935f8 ("enable debug build by setting a settings Reason: so the debug possibility is always available and is by default off for performance reason", 2023-07-14) Martin Marmsoler
198fb7a ("Update src/app/Application.cpp", 2023-07-14) Martin Marmsoler

1e57e7d ("Spanish translation", 2023-06-17) José Miguel Manzano 
3c92cc0 ("Adds "Hide Untracked Files" option to DoubleTreeWidget cogwheel context menu", 2023-07-02) pvacatel
a80ffed ("Fixes code format according to clang-format", 2023-07-03) pvacatel
b202f1a ("Reverts format changes to test/Settings.cpp", 2023-07-04) pablov
0a935f8 ("enable debug build by setting a settings Reason: so the debug possibility is always available and is by default off for performance reason", 2023-07-14) Martin Marmsoler
198fb7a ("Update src/app/Application.cpp", 2023-07-14) Martin Marmsoler

…as a list in TreeViews. Resolves Dense layout issue Murmele#547

Conflicts:
	.gitignore
	src/ui/FileContextMenu.cpp