Handle default styles

Logic moved to Format potentially enables configuration of default style
move line optimization to doc
add/enable failing insert tests
Add newline count to line's own length

This also means a line ALWAYS has a trailing newline, regardless if
format is there or not. Deleting the trailing newline is not possible
(result in a no no)
add tests for deleting line's trailing newline
Merge branch 'line' into refactor
fix trailing newline behavior

Should not be able to insert, delete or format at or beyond trailing
newlne. Enforce at findLeafAt
Fix editor insert implementation
remove dead code
Fix editor _deleteText implementation + add tests
Use jasmine matchers for delta
add _formatAt tests
make expect.equalHTML a matcher

Also git add forgotten file test/helpers/matchers.coffee
notes for applyDelta
some refactor
add tests for selection._normalizePosition
add tests for selection helpers
fix selection helpers
add tests for get/set range and check focus