Some issues introduced in #954
(https://github.com/BoostIO/Boostnote/pull/954#issuecomment-336344915):
- search by `#tag1 #tag2` returns the results of only `#tag2`
- search by `#tag1 content` is as same as AND search by `#tag1 content` (and
`#tag1` is regarded a word, not a tag)
- search by `content #tag1` returns the results of only `#tag1`
This commit fixing these:
- search by `#tag1 #tag2` returns the results of only `#tag2`
- search by `#tag1 content` is as same as AND search by `#tag1 content` (and
`#tag1` is regarded a word, not a tag)
- search by `content #tag1` returns the results of only `#tag1`
NOTE: the examples works without `#` character too, because
`findByWord()` checks the tags too.
