Refs 114: Character sprite scaling fix

[Whyshchuck]

In order to solve problems listed in
#141
room's method update_character_scale function name had been changed as it's private no more.
unfortunately in next PR:
#142
one of references in popochiu_region restored the outdated name.

Following PR covers fix of:

• above mentioned bug and
• avoids transfer of characters' position to the next room (via character's position_stored variable)

[stickgrinder]

LGTM, merging