preprocessor: Capitalize first word of two error messages

Like all WML preprocessor diagnostics, these aren't translatable
strings, so this is a valid candidate for 1.12.
preprocessor: 'any argument' -> 'any arguments'

Like all WML preprocessor diagnostics, these aren't translatable
strings, so this is a valid candidate for 1.12.
Great Ogre unit for use in LoW.
First topic of an editor help section.
put simple_rng methods in own file.
add new rng

the plan is to have random_new::generator which can be a rng_synced or not dependng on whether we are in a synced context (for example select events are no synced context)
add replay_helper class
add config_of function
add synced_context class

the intention  is to fix #20871 and implement #21697, to sync
prestart/start events, and to implement
http://forums.wesnoth.org/viewtopic.php?f=6&t=39611 in the next patches,
give a better error message.

when a player leaves a mp game during a lua call and the other player
pressed escape, lua catches the error that should exit the game, idk
wether i can fix that but at least i can give a better error message.
use rand() instead of get_random() for side shuffle

1) i think it's better to use a simple rand function for things that are
never synced, because everyone knows that rand() isn't synced.
2) my plan is to delete the get_random() function.
fixes wrong side during end turn events in replay
serverside code for the new rng.

i might have to change this code again because the following might be
true: 'instead of checking wether we already gave a random seed it'd
would be better to accept only seed requests ffrom the currently active
side'
use the new synced_context system

the main intention of that patch is to fix gna.org/bugs/?20871,
gna.org/bugs/?21697, some OOS erros related to use of multiple
[get_global_variable] with different sides in one event.
To remove the deterministic random for traits and similar as discusssed
here http://forums.wesnoth.org/viewtopic.php?f=6&t=39611. And to sync
start end prestart events.

this patch unifies how side commands (like attack, recruit, ...) are
executed, during human turn, replay or ai turn by makeing them al call
the same function scned_context::run_in_scned_context.
We also use the new random generator which is automaticly synced during
the execution of scned_context::run_in_scned_context, and otherwise not.
So we cannot cause oos anymore by using rand= from an unsnced command
like "select"
Alternativeley we can also set the new random synced by using the new
RAII object set_sconext_sycned, this happens for example during prestart
events.
Unlike the old random generator, the new random generator is not
determinstic by default because it asks the server (or itself in a SP
game) for a new seed, at every side command (attack, move, recruit ...)
that requires random ,similar to how the previous rand for attacks
worked (it doesnt ask at the beginning, just the first time it is needed
unlinke how attacks worked before). That way we can also unify the rng
for attacks and for other random choices.

this commit breaks ai's advancement aspects, but form what i have heared
that should be fixable.
this commit might create some unused code, that shall be cleared,
especialy i want to remove random.hpp/cpp, rng.hpp/cpp
this commit might contain spelling mistakes.
adding wesnoth.is_synced() #21697
fix a bug when players leave in mp.

as pointed out by EliDupree:
http://www.wesnoth.org/irclogs/2014/03/%23wesnoth-dev.2014-03-19.log
fix a oos bug on sighed enemy units in mp.

movements is still treated specialy and doesn't use
run_in_synced_context by default, because some funtions use the return
value of move_unit.
fix a mp bug

it might happen that we land in playmp_controller::play_side but still
have data in the replay that we recieved from network earlier.

this commit also contains small code cleanups.
change the way the server accepts require_random

removed has_given_random_seed_.
ignore end_turn_exception from get_user_choice

also removes some usless code from persist_var, that was already moved
to get_user_choice.

also adds some logs in do_replay_handle