Improved spellcheck
Fixed memory leak caused by not freeing the suggestion list.
Fixed cursorPositionChanged not rehighlighting text when the cursor is moved to
a token with the same in-block index but in a different block.
More efficient rehighlightning on coursor move: rehighlights only needed block
instead of the whole document and only when we leave the edited token.
Some refactoring to make code more readable.