Add OT for InsertText and SplitParagraph at the same position.

The person typing text should keep typing in the same line
without any unexpected jumps.
The person splitting the paragraph should get that without having
the other typing in the new one.

Also added tests for all 3 position cases (before, same, afteR)
in InsertTextSplitParagraph.
Merge pull request #546 from adityab/split-insert-ot

Add OT for InsertText and SplitParagraph at the same position.
Remove unused webodf/tests/test_odt directory

This directory has never been used, even within the commit that added it
Remove try-catch blocks that immediately rethrow the caught exception

These effectively act as slightly expensive no-ops. There is no need
for them to be present.
Fix ListStylesToCss test that fails in Firefox
Log additional information if a stylesheet rule fails to insert
Add test document demonstrating list escape character issues
Escape list prefix, suffix and bullet chars in the CSS rules

Various browser cope differently with unescaped characters in a CSS
content block, though all browsers agree it is a bad thing. WebKit
will throw an error, Chrome & FF will "guess" where the rule ends
(and usually get it wrong).

This patch does 2 things to fix this:
- Consistently use double-quotes to quote strings
- Escape backspace and double-quote chars in the CSS-related content

The vast amount of testing code is primarily creating a string tokenizer
able to parse out the displayed text across Chrome/WebKit + FF. As there
is no simple way to get the "rendered text" from a pseudo-element, a lot
of code is required to compute this. There are tests included for the
hand-rolled tokenizer as well to ensure proper function.

No tests have been added for OdfCanvas, as the existing list logic in
here is destined (sooner rather than later) to be merged into the newer
list CSS translation class.