Use dot (".") as surface name to select current

[winex]

hi! we've been playing Space Exploration (lots of surfaces: planets, orbits, asteroid belts) and it's hard to change name in settings every time to delete chunks on another surface, so i added a feature to use . as current surface name which the player is currently on. i hope no mods names any surface like this, so it won't bug anyone.

tldr;

• set '.' as surface name in settings to delete chunks only on which you're currently on/viewing
• remote commands doesn't accept it. works only from GUI

if you're not satisfied with any changes - i'll edit and add commits as you wish.

p.s. you probably don't want to zip .git/ directory when releasing mod. it's bigger than the mod itself. and thanks for the useful mod! ;)

[winex]

updated against the last version...