Various validation improvements

Mainly to address http://www.fabrikar.com/forums/index.php?threads/ajax-validation-never-ending-in-forms.36907/ but other minor issues addressed also.

1. Move element validation to element.js in order to allow multiple element validations in parallel.
2. Clean code to minimise JsHint messages.
3. Remove ajaxmethod - post is default and since post must be used (since gets indicate a prefilter), this has no point.
4. Maximise use of mootools Request events to ensure clean use of spinner.
5. Correct typos in Fabrik Events (by adding corrected name rather than replacing existing)
6. Make consistent error reporting console log format.
Address bug found by Rob
Missing _
Fix bug when r not array

Flatten only applies when r is an array.
Minor tweak to error logging ...

... to improve error message.
Fix remaining stuck spinners etc.

element.js:
1. Fix remaining stuck spinners
2. Make validation messages display correctly (J3 tips still to be
fixed).
3. Tidy up setErrorMessage
4. Add ajax debug status messages
5. Add validation error message display to user
6. Spell check

form.js:
1. Fix remaining stuck spinners
2. Spell check
Fix spurious success messages...

... when ajax validation is off.
merge
case insensitive replaceLast()
set component name to placeholder
added bootstrap classname to listfields gui element
admin lang
update user ajax example text
edgecase fix for calcs in views
dbjoin element getEmail value - if "please select" then return "". Also sort filter options if element isjoin()
Merge branch 'joomla3' of github.com:Fabrik/fabrik into joomla3