add [do_command] wml action tag

[do_command] executes commands like attack, move, recruit, etc.,
similar to those that may be found in [command] tags in replays.
These are executed in game immediately in a synchronized context,
similarly to as if a human or ai controller had ordered them.

It is also possible to use the command to fire a WML game event,
or to execute lua code from a synchronized context.

Only some of the children of [command] are valid in this tag.

With this tag, [issue_attack_command] and [issue_move_command] are
both deprecated and will be removed shortly.

Thanks to gfgtdf for both the idea and the implementation.
refactor test #6 to use [do_command]
change a warning to a log message, related to [attack] command

The core code seems to handle it just find when defender_weapon
is not present, so this warning seems unnecessary. This will make
it easier to use [do_command].
make [command] [attack] handler a bit friendlier

Now, it won't warn about mismatch with gamestate when you don't
specify attacker_type or defender_type.

Simplify unit test 6 accordingly.
remove [issue_attack_command], [issue_move_command]

also add some comments to [do_command] which replaces them.
update changelog
rename wml unit tests

tests should have helpful names and not numbers
add sanity checks for unit test mechanism

also, reorganize the test schedule file
Fix a bunch of typos: syced -> synced

This commit is the result of running this command in src/ directory:
git grep -lz 'syced' | xargs -0 perl -i'' -pE "s/syced/synced/g"

Thank you stackoverflow :)
http://stackoverflow.com/questions/1583219/awk-sed-how-to-do-a-recursive-find-replace-of-a-string

(I used the "git safe" version)
fix replay of delayed shroud updates (21986)

we have to enable the undo stack during replays to make these work. This
was accidently disabled during pr 121.
fix linger mode in mp (21985)
save replaydata of the undostack

not saving these might result in currupt replays when redoing a move
from a saved game.
Reallow selection of another unit on same side without deselect first
Simplify condition check for mouse action/move.
Remove accidentally committed windows binary
fixup test directory

C++ tests load from /data/test/ again, and the _main includes in
data/ and data/test/ are fixed up to accomodate this.

This fixes up cc138a4ed96f3ac1f8c5130aa6842d1429013da4
fixup run_wml_tests

Prev version could sometimes give an error if test timed out and
error.log was not created, so add a check for if error.log exists.

Also refactor so the error log handling is in its own function.
Merge branch 'master' of git://github.com/wesnoth/wesnoth