Refactor and cleanup migration code

Hi

v4:

rebase on top of new qemu and new migration-errors series

v3:
this patch applies on top of my previous "migration error" patches. All error handling has been moved to that series, except for "propagate error correctly", without this refactoring, it is quite complicated to apply it.

Please, review.

Later, Juan.

v3:
- more checkpatch.pl happines
- split error handling in a previous series
- make Anthony happy. current_migration is still a pointer, but points to a static variable. We can change current_migration when we integrate kemari.

v2:
- make Jan^Wcheckpatch.pl happy
- Yoshiaki Tamura suggestions:
- include its two patches to clean things
- MAX_THROTTLE define
- migration_state enum
- I removed spurious differences between migration-{tcp,unix}
- better error propagation, after this patch:
migrate -d "tcp:name_don_exist:port"
migrate -d "tcp:name:port_dont_exist"
migrate -d "exec: prog_dont_exist"
migrate -d "exec: gzip > /path/dont/exist"
fail as expected. Last two used to enter an infinite loop.

The fixes part should be backported to 0.14, waiting for the review to do that.

Later, Juan.

v1:
This series:
- Fold MigrationState into FdMigrationState (and then rename)
- Factorize migration statec creation in a single place
- Make use of MIG_STATE_*, setup through helpers and make them local
- remove relase & cancel callbacks (where used only one in same file than defined)
- get_status() is no more, just access directly to .state
- current_migration use cleanup, and make variable static
- max_throotle is gone, now inside current_migration
- change get_migration_status() to migration_has_finished() and actualize single user.

Please review.

Later, Juan.

Juan Quintela (23):
migration: Make *start_outgoing_migration return FdMigrationState
migration: Use FdMigrationState instead of MigrationState when
possible
migration: Fold MigrationState into FdMigrationState
migration: Rename FdMigrationState MigrationState
migration: Refactor MigrationState creation
migration: Make all posible migration functions static
migration: move migrate_create_state to do_migrate
migration: Introduce MIG_STATE_NONE
migration: Refactor and simplify error checking in
migrate_fd_put_ready
migration: Introduce migrate_fd_completed() for consistency
migration: Our release callback was just free
migration: Remove get_status() accessor
migration: Remove migration cancel() callback
migration: Move exported functions to the end of the file
migration: use global variable directly
migration: another case of global variable assigned to local one
migration: make sure we always have a migration state
migration: Use bandwidth_limit directly
migration: Export a function that tells if the migration has finished
correctly
migration: Make state definitions local
migration: Don't use callback on file defining it
migration: propagate error correctly
migration: make migration-{tcp,unix} consistent

 migration-exec.c |   39 +----
 migration-fd.c   |   42 ++-----
 migration-tcp.c  |   76 ++++------
 migration-unix.c |  112 ++++++---------
 migration.c      |  404 ++++++++++++++++++++++++++---------------------------
 migration.h      |   85 ++----------
 ui/spice-core.c  |    4 +-
 7 files changed, 303 insertions(+), 459 deletions(-)

1.7.6.2