Use Object.keys for iteration
Refactored application of list styles

Moved the code that parses ODF lists styles and creates rules for them
into a separate object. This is done as the second step in removing
duplicate/redundant code from OdfCanvas.js around some list style
handling.
Removed duplicated stylesheet error handling
Implement label-width-and-position mode for list layout

Remove the partial handling of list indentation and implement the default
option for list-level-position-and-space-mode.

http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#property-text_list-level-position-and-space-mode
Implement label-alignment mode for list layout

Add handling for the label-alignment list style element. This commit does
not implement the text:label-followed-by attribute when the value is
"listtab" so for now a hard coded padding has been substituted

http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part1.html#__RefHeading__1416522_253892949
Added some layout tests for list styles

Added one test for label-alignment styling and another test for
label-width-and-position mode