Add test case for title change

[pranomostro]

When user A changes the title for a conference, the tox_callback_conference_title() is
called for everybody except A. This program tests this case.

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This change is 

[Diadlo]

Why new test created instead of adding in conference_test?

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Reviewed 3 of 3 files at r1.
Review status: all files reviewed at latest revision, 2 unresolved discussions, some commit checks failed.

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auto_tests/self_conference_title_change_test.c, line 35 at r1 (raw file):

static const char *newtitle = "kitten over darknet";

static void cbtitlechange(Tox *tox, uint32_t conference_number, uint32_t peer_number, uint8_t *title, size_t length,

title should be const. I.e. const uint8_t *title

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auto_tests/self_conference_title_change_test.c, line 56 at r1 (raw file):

    t = tox_new(&to, NULL);

    tox_callback_conference_title(t, cbtitlechange);

Forget & before cbtitlechange

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Comments from Reviewable

[iphydf]

@Diadlo I prefer more self-contained test binaries rather than putting a lot of tests together in one file. It takes a bit more time to run them because they don't share the same tox network context, but they are more self-contained, because they don't share the same tox network context :).

[iphydf]

Please enable the checkbox "Allow edits from maintainers." on the bottom right.

[pranomostro]

Done.

[iphydf]

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Review status: 0 of 3 files reviewed at latest revision, 2 unresolved discussions.

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Comments from Reviewable