Proper link in changelog docs
Write elements in canonical order
Remove an unused import
Proper changelog for #40
Merge branch '0.1-maintenance'
libearth.parser.heuristic module is gone
Log exceptions if any rise in get_format()
Add missing tests for get_format() function
Fill <title> to <description> if there's no title
Merge branch '0.1-maintenance'
Fill <id> to the feed url if there's no <id>
Merge branch '0.1-maintenance'
.sessions get touched only once at a transaction

Close #43
Internal hints field for Element
Writing hint values
Sort hint tags in canonical order
Reading hints
Release 0.1.2
Merge branch '0.1-maintenance'
Added Link.html property