Update jQuery to 1.4.0.

In order to get the Chosen jQuery plugin working.
Install the Chosen jQuery plugin.

Version is the current HEAD + a patch sent upstream [1].

[1] https://github.com/jiru/chosen/commit/cfcdc325f5cb5e474cca318d5e21094797e380df
Use Chosen for language selection dropdowns.

This will hopefully ease the selection of languages.
Adapt Chosen dropdowns CSS to fit Tatoeba’s style.
Fix Chosen dropdowns bug.

Chosen dropdowns are getting hidden once they get out of the
page contents’ div. This is especially annoying for dropdowns
that are on the bottom of the page, such as the ones in
/activities/translate_sentences. I’m not sure this change won’t
break other things but it sounds okay. For the record, this line
was introduced by commit b0b52ad6283f6be54786196c7ced3c4d64edf6a3.
fix #357 (bidirectional search results string)
Fix the romaji/furigana tool.

Since we use a VM with English locale for both production and
development, update the escapeshellarg() hack [1]. I hope we
can get rid of this crap one day.

[1] http://php.net/manual/en/function.escapeshellarg.php#99213
Revert "test #180."

This reverts commit a4dd5f6bdd8356ff39bd904c7aafe60e580ab0f6.
#376 Fixed undefined index 'correctness'
#364 Fixed language select height in sentences/show
#364 Fixed padding/margin for language select in annexe content
Merge pull request #364 from Tatoeba/lang-selector

Better language selection dropdown
#388 Updated google analytics
#387 Fixed contributions pagination when filtering by lang
Fixed CSS on wall and members page.
#375 storing Auth->user() in CurrentUser was done at the wrong place
#390 Option for advanced language selector.

Also fixed redirect when saving settings (to redirect to the settings
page rather than the profile page).
Updated donate page.
#364 Fixed language selector in translation form.
#364 Language selector for changing language of a sentence.