Remove unused database columns and repeated SQL code
Merge remote-tracking branch 'origin' into CP-63

Conflicts:
	Confidence/SQL/table.sql
Remove unused class
Code cleanup, use prepared statements for SQL queries, add more cases to facilitator signup validation
Better form validation and error messages for facilitator login
Form validation and error messages for student login
Merge remote-tracking branch 'origin' into CP-63

Conflicts:
	Confidence/SQL/table.sql
Restrict length and character type of login input forms
Form validation and error messages for creating a sitting
Show confirmation message after creating a new sitting
Merge pull request #12 from charbelZeaiter/CP-63

CP 63