* Fix test::print for Unicode
The print function was not generating correct translations when
the input has Unicode (non-ASCII) in it. This is due to its use of
String::len, which gives the length in bytes, not chars.
* Fix multi-code point auto pairs
The current code for auto pairs is counting offsets by summing the
length of the open and closing chars with char::len_utf8. Unfortunately,
this gives back bytes, and the offset needs to be in chars.
Additionally, it was discovered that there was a preexisting bug where
the selection was not computed correctly in the case that the cursor
was:
1. a single grapheme in width
2. this grapheme was more than one char
3. the direction of the cursor is backwards
4. a secondary range
In this case, the offset was not being added into the anchor. This was
fixed.
* migrate auto pairs tests to integration
* review comments