tests: use a fakesink to avoid beeps and format changes.

If the tests would use alsasink, the might get negotiated to raw/int and that
would require more logig in the handoff callback (which assumes float).
sink-bin: encodebin starts we a queue already so we can save ours
tests: make tests that play silent
main-page-sequence: fix expanding the loop

We were accessing an uninitialized variable.
setup: reformat comment
main-page-patterns: don't step over pattern length in ',' comamnd
sequence: when extending the sequence, ev. extend loop_end

If loop_end was the same as the old length, then not only increase the length,
but also the loop_end.
sequence: improve handling of loops when length changes

Add tests for expansion and clipping logic.
main-page-sequence: don#t use MOD4 as a modifier

The super key is heavily used by gnome3. Use Ctrl+shift instead.
Fixes: #13
machine: only check the name to determine unique pattern names

Machines can be renamed and this would break the unique checks.
main-page-patterns: ensure we don't switch patterns when cancel cloning one
value-group: add a range-randomize variant

The variant uses the first and last value in the pattern to limmit the random
number range.
tests: fwrite never returns a values < 0

Fixes a (misleading) gcc warning.
pattern: eliminate the id parameter

We can reference patterns in a song file by name and the machine of the track.
This avoid keeping name and id in sync. Before we were getting into troubles
when the machine got renamed.
tests: update the test song files
xsd: update schema
NEWS: collecting news and release planning
tests: small test rename
ui: use utf-8 char instead of 3 dots for ellipsis
tests: add a test for loading from legacy format