Bugs and text corrections

notemyprogress/ajax.php

notemyprogress/amd/build/metareflexion.js

notemyprogress/amd/src/student_sessions.js

notemyprogress/classes/debug_text.php

notemyprogress/classes/lib_trait.php

notemyprogress/classes/metareflexion.php

notemyprogress/classes/report.php

notemyprogress/lang/en/local_notemyprogress.php

notemyprogress/lang/es/local_notemyprogress.php

notemyprogress/lang/fr/local_notemyprogress.php

notemyprogress/metareflexion.php

notemyprogress/templates/metareflexion.mustache

notemyprogress/templates/sessions.mustache

notemyprogress/templates/student_sessions.mustache