Fixed a lot bugs/security exploits

Profiles can't be hacked anymore, added some security control and
removed those malicious "hidden uid"
Errors now are now shown correctly while editing the profile
The level of the research you're doing in the Blacksmith/Armoury is now
displayed in the research queue
Hugely fixed the battle system, a big thanks to kirilloid for helping me
by providing his formulas :)!
Some general clean-up and bug fixing of little errors
Added some string constants to the language file (en.php)

GameEngine/Lang/en.php

@@ -63,7 +63,7 @@ define("LOGIN_PASS_EMPTY","Enter password.");
 define("EMAIL_ERROR","Email does not match existing");
 define("PASS_MISMATCH","Passwords do not match");
 define("ALLI_OWNER","Please appoint an alliance owner before deleting");
-define("SIT_ERROR","Sitter already set");
+define("SIT_ERROR","Sitter already set or player inexistent");
 define("USR_NT_FOUND","Name does not exist.");
 define("LOGIN_PW_ERROR","The password is wrong.");
 define("WEL_TOPIC","Useful tips & information ");
@@ -79,6 +79,7 @@ define("ID_NO_EXIST","There is no user with the id ");
 define("SAME_NAME","You can't invite yourself");
 define("ALREADY_INVITED"," already invited");
 define("ALREADY_IN_ALLY"," already in this alliance");
+define("VAC_MODE_WRONG_DAYS","You've inserted a wrong number of days");
 
 //COPYRIGHT
 define("TRAVIAN_COPYRIGHT","TravianZ 100% Open Source Travian Clone.");
@@ -112,6 +113,7 @@ define("GO2MY_VILLAGE","Go to my village");
 define("VILLAGE_CENTER","Village centre");
 define("FINISH_GOLD","Finish all construction and research orders in this village immediately for 2 Gold?");
 define("WAITING_LOOP","(waiting loop)");
+define("CROP_NEGATIVE","Your crop production is negative, you'll neaver reach the amount of requested resources.");
 define("HRS","(hrs.)");
 define("DONE_AT","done at");
 define("CANCEL","cancel");