Do not call updateFilterText from INI Parser. (#81)

The INIParser creates a fresh Subscription and assigns the filterText. We can completely bypass updateFilterText that will introduce unnecessary copies and try to figure out added and removed filters.

I am pretty sure we don't even need to copy the this._curObj, because the code afterwards will create a new object depending on this._curSection.

The timings for loadFromDisk are quite unstable, probably because of Promises, but this seems to improve time by about 100ms.