Suspend/break a long running script

This patch adds the ability to interrpt or suspend a long running script. If suspended, the script can be resumed with standard API at a later point.

One can also do some application work (like driving a C++ GUI) inside the app QuerySuspend function.

Diff file (against Squirrel 2.5 work sources):

Source files:

How to use:

  int SQMyQuerySuspend( SQVM *vm ){ 
     if( /* too long time */ ){
       return SQ_QUERY_BREAK;
       // or return SQ_QUERY_SUSPEND; 
     }
     /* Do some processing / nothing */
     return SQ_QUERY_CONTINUE;
  }
  
  // In init section 
  SQVM *vm = /* from somewhere */;
  vm->SetQuerySuspendFn( SQMyQuerySuspend );
  // ... continue