Early exit from abstract_ferns.grow_giant_tree_fern

(very) small performance increase
Renamed "leave" to "leaf" where appropriate
Refactor abstract_ferns.grow_giant_tree_fern

Arguably more readable; definately more maintainable

Potentially slower but if it is the difference would be negligable
Renamed SeTTiNGS.txt to settings.lua

It's a Lua file... the extension should reflect what it actually is
Stop polluting global namespace
Bump minor version number
Removed obsolete or useless code

Some commented code makes no sense because there is not comment as to why it's commented out. Removed.
derp
typo (bug fix)
Fixed stupid node names
Renamed config/settings var names
Moved ferns "'module' loaded" asserts to top of files
Random lady fern face direction
Minor changes
Early exit
Updated horsetails
Updated "lady ferns"
Re-wrote abstract_ferns.grow_tree_fern()
Added comment for node string tests