ReleaseNotesGeneratorForm: add label with help text
ReleaseNotesGeneratorForm: fix line breaks in TextBox; add new lines to HTML code
ReleaseNotesGeneratorForm: HTML table: clipboard content can also be pasted as text (HTML code) to text editor; prepare for unit tests
update GitExtensionsTest submodule
ReleaseNotesGeneratorForm: make buttons more descriptive
ReleaseNotesGeneratorForm: refactoring
update submodule
Submodule GitExtensionsTest updated

Submodule GitExtensionsTest:
    > 3d05c92 - mark test explicit instead of ignored
fix #1883: resize icon on initialization
Merge branch 'pr/n1910_mexx'
Set the default buttons in the "Reset Current Branch" popup to fix Enter/Escape keys not working.
Merge pull request #1911 from peppy/master

Set the default buttons in the "Reset Current Branch" popup to fix Enter/Escape keys not working.