Rather than try to correct the issue of the Comparator crashing in
BookmarkManager because the Strings/HistoryItems were null, I modified
the HistoryItem object so that the title, url, and folder strings can no
longer be null but will instead be empty if set to null, this then
prevents the BookmarkManager from throwing an NPE when sorting the items
by title.
* remove all trailing spaces
* some files used spaces instead of tabs like the rest of codebase - fixed
* make use of IDE "optimize import" feature
* make use of IDE "auto format" feature to fix some missing spaces here and there
