Fix wrong bold font due it no longer being allowed to create fonts us…

…ing dot syntax (wireapp#17)

Fix: Chinese list line spacing (wireapp#15)

* add font to tab

* add attribute to break

* clean up

Create NSMutableAttributedString.paragraphTailTruncated() (wireapp#13)

* create test for paragraphTailTruncated()

* clean up

Create NSMutableAttributedString.paragraphTailTruncated() (wireapp#13)

* create test for paragraphTailTruncated()

* clean up

Modify the parser to keep any non markdown attributes (wireapp#12)