Hebrew: Added acronym bypass.
Uyghur: Acronyms are written as words.

Just as in Arabic and Farsi, SQL for example is written as Es kyu El
(إس كيو إل) as words, no need to check and no capitals either.
zh_CN: Acronyms and caps are different

No need to check.
zh_HK: Acronyms and caps are different

No need to check.
zh_TW: Acronyms and caps are different

No need to check.
Cleanup: Remove unused test ODT file for odf2xliff roundtrip testing
Cleanups
Cleanup: Just set everything when instantiating Translatable
Cleanup: Rename _process_placeables to don't confuse with _process_placeable
Cleanup: The translatable should know if it contains translatable text
Cleanup: Remove unused parameter
Cleanup: Rename parameter to increase readability
ts2: Improve the output of processed TS files

 - Pretty-print empty tags without self-closing them
 - Always preserve TS doctype
 - Add a test reusing existing ts data

This bumps the lxml requirement to 2.3.6 due to requiring the doctype argument
Cleanup: Combine context managers and get it out of function

There is no need to have three separate context managers here. Also
putting it out of the function will allow further reuse and shortens
the function incresing code readability.
Several cleanups

These are meant to increase code readability and provide useful docstrings.
Requirements: Match Pootle Sphinx requirement
Cleanup: Remove intermediate _retrieve_placeables function

This way it is easier to understand the code.
tools/pretranslate: Remove dependency on xliff (and therefore lxml)

Fixes #1909
README: Include some extra badges
Minor cleanup