Store doc's babs_filename without home encoding

This is the way was supposed to be. All the filenames are supposed to be
stored without home encoding, i.e. with explicit paths.

Should fix issue #177 and make PR

https://github.com/franko/lite-xl/pull/174

unneeded.

It may also address issue #174 but would need further verifications.

data/core/doc/init.lua

@@ -67,7 +67,7 @@ end
 
 function Doc:set_filename(filename)
   self.filename = filename
-  self.abs_filename = common.home_encode(system.absolute_path(filename))
+  self.abs_filename = system.absolute_path(filename)
 end