[qtc] added syntax highlighters for yaml, spec, desktop and changes

Syntax highlight files copied from kate editor. changes highlighter
modified from rpmspec highlighter.

Signed-off-by: Juha Kallioinen <juha.kallioinen@jolla.com>
(cherry picked from commit 8383a4f2f55f11a9b3cd9a9bf84281e03573657a)
[qtc] more room for revision in the about dialog

Signed-off-by: Juha Kallioinen <juha.kallioinen@jolla.com>
(cherry picked from commit e8d1be95c4ea8e5c200ca5b984f1c2a25148cc81)
Project file is writable when examples are copied

(cherry picked from commit 4522d599054f6eaef3c36b1502f2723d01369fe7)