Update patches and packaging for 3.4.1

When upgrading to 3.4.1 some patches need updating, and some look obsolete. In the first commit of this PR, four that need updating are included.

Also 003_data_path.diff needs updating, and this is tentatively done in the third commit of this PR. Seems to work, but it can maybe be further reduced.

For the other Debian patches, I believe these are obsolete:

• 004_userinfo.diff (~/.ddd_userinfo not used any longer, debian/rules can remove it too)
• 005_gcc44_fix.diff (applied upstream)
• 006_unumlaut_fix.diff (upstream converted ddd.man.in to UTF-8)
• machine_code_window_fix.diff (applied upstream with modification: ", ")
• fix-ftbfs-gcc-9.patch (not needed any longer)
• 007_reproducible_build.diff (build date is not used/displayed any longer)

so these patches are dropped in the second commit.

With all commits applied I can build the binary packages.