Added 'const' to arguments in get_one_option and find_typeset()

One should not change the program arguments!
This change also reduces warnings from the icc compiler.

Almost all changes are just syntax changes (adding const to
'get_one_option function' declarations).

Other changes:
- Added a few cast of 'argument' from 'const char*' to 'char *'. This
  was mainly in calls to 'external' functions we don't have control of.
- Ensure that all reset of 'password command line argument' are similar.
  (In almost all cases it was just adding a comment and a cast)
- In mysqlbinlog.cc and mysqld.cc there was a few cases that changed
  the command line argument. These places where changed to instead allocate
  the option in a MEM_ROOT to avoid changing the argument. Some of this
  code was changed to ensure that different programs did parsing the
  same way. Added a test case for the changes in mysqlbinlog.cc
- Changed a few variables that took their value from command line options
  from 'char *' to 'const char *'.

client/mysql_upgrade.c

@@ -270,7 +270,7 @@ static void add_one_option_cnf_file(DYNAMIC_STRING *ds,
 }
 
 static my_bool
-get_one_option(const struct my_option *opt, char *argument,
+get_one_option(const struct my_option *opt, const char *argument,
                const char *filename __attribute__((unused)))
 {
   my_bool add_option= TRUE;
@@ -301,10 +301,17 @@ get_one_option(const struct my_option *opt, char *argument,
     add_option= FALSE;
     if (argument)
     {
+      /*
+        One should not really change the argument, but we make an
+        exception for passwords
+      */
+      char *start= (char*) argument;
       /* Add password to ds_args before overwriting the arg with x's */
       add_one_option_cnf_file(&ds_args, opt, argument);
       while (*argument)
-        *argument++= 'x';                       /* Destroy argument */
+        *(char*)argument++= 'x';                /* Destroy argument */
+      if (*start)
+        start[1]= 0;
       tty_password= 0;
     }
     else