#241 Possibility for admins to change users.level
#241 Possibility for corpus maintainers to edit sentences.correctness
#241 Sentences with correctness -1 displayed in red.
#241 For new sentences/translation, sentences.correctness = users.level.
#241 Sentences with correctness -1 not exported into CSV files.
#241 Added info in profile that a user's sentences are added as "not approved".
converted text fields to radio buttons
#241 'correctness' for sentences lists.
#241 Changed max correctness and max level, fixed value for radio buttons.
#241 Fixed CSS for users/edit, fixed value of level radio buttons
Merge pull request #267 from Tatoeba/sentences-correctness-radio

Sentences correctness radio
#241 Removed legend from correctness form and added some margin between the radio buttons.
#241 SQL script to update the sentences.correctness and users.level columns
#241 Fixed SQL script

CakePHP interprets TINYINT(1) as a boolean, so it won't save negative
values. Using TINYINT(2) instead.
#241 Restrict modification of sentences correctness to admins for now (just a few days)
Merge pull request #262 from Tatoeba/sentences-correctness

Sentences correctness