repo: make changelog easier to merge

The changelog now uses union merges to reduce conflicts.
Changed the EOL in changelog.html to CRLF to help even more.

Signed-off-by: Mloc-Argent <colmohici@gmail.com>
tools: fix EOL handling in AddToChangelog.exe

AddToChangelog.exe was using a mix of \r\n and \n EOLs.
Fully uses \r\n now.

Signed-off-by: Mloc-Argent <colmohici@gmail.com>
Merge pull request #3913 from Mloc/tg-changelogmerge

Fix changelog merging + fix AddToChangelog.exe