If we had something like c:(test) sort:(mtime, desc), then
we would run into an sql error eventually, since we
would have added an implicit AND token before the sort
condition. This is wrong, as a sort is not a filter.
So, as a quick hack to fix this, just remove a preceeding
boolean (as dirty as it may be, but it does the job for now).
Purpose is to seperate certain logic from SQLite and generalize it more.
Even though we only have Sqlite atm, in general the database layers
must be stupid as possible, while QSSQuery should do most of the hard work.
Fixes in Tokenizer logic.
Switched to C++17.
