Change the comparison algorithm of titles when searching through the index.
We use a comparison of byte arrays instead of String comparison.
If we find the exact title when doing the binary search, it's no use searching more.
It's a small optimization.
Externalize utf8 encoding/decoding functions
Revert to a String comparison in the Title search instead of comparing the byte arrays : it gives the same result and probably uses more CPU
Convert the character ° to _ when normalizing the titles.
Fixes #7