If an initial states without incoming transition has to be merged into
another one, its outgoing edges can be reused by just changing their
source.
* spot/parseaut/parseaut.yy (fix_initial_state): Implement this here.
* tests/core/522.test: Add more tests.
* tests/core/readsave.test: Adjust one expected output.
* doc/org/hoa.org: Mention the completeness change.
* NEWS: Mention the new feature.
Fixes#522 reported by Raven Beutner.
* spot/parseaut/parseaut.yy: Make sure all edges leaving
the initial state have the same color.
* THANKS: Add Raven.
* NEWS: Mention the bug.
* tests/core/522.test: New file.
* tests/Makefile.am: Add it.
