created pdf.py to generate roster using Pisa xhmtl2pdfenv
Display absent trainees by gender on the absent trainee roster
Merge branch 'absent-trainee-roster' of https://github.com/attendanceproject/djattendance into absent-trainee-roster

Conflicts:
	ap/absent_trainee_roster/admin.py
	ap/absent_trainee_roster/views.py
Fixed bug in calculate_days and made some changes to absent trainee roster pdf
Pulled from github in order to push changes
Merge branch 'absent-trainee-roster' of https://github.com/attendanceproject/djattendance into absent-trainee-roster

 into a topic branch.