Restructure jquery/ui directory, add i18n
Some form improvements

- Implement jquery-ui datepicker in Dateselect
- Rework Radio and Checkbox to support attributes
Cleanup
Another tweak to @method in doc block

The methods getImgUrl() and getImgTag() are used in multiple services, but some have additional parameters. This is an attempt to document them so that tools like scrutinizer-ci won't complain about the magic method calls generated by every service consumer.
Fix empty button title, and empty placeholder attribute in DateSelect
Fix issue in Radio form element
Merge pull request #204 from geekwright/jquidate

Some form improvements and cleanups
Upgrading TinyMCE to 4.1.4
Merge pull request #205 from mambax7/master

Upgrading TinyMCE to 4.1.4
Standardize JSON output

json_encode options that we should use for editable json output (like composer.json) are only available on PHP 5.4 and above. This borrows the same routine used in composer, so that we get consistent easily editable 'pretty printed' output under all PHP versions.
Several small fixes, including xcaptcha form issue
Merge pull request #207 from geekwright/json

Standardize JSON output
Merge pull request #208 from geekwright/fixes

Several small fixes, including xcaptcha form issue
Fix to earlier fix :(

Somehow, the last change to this file was not what was intended (or tested.)
Merge pull request #209 from geekwright/fixfix

Fix to earlier fix :(