change date to date time for creating mission, training and announcement
allow students to edit their submissions.
enable html-editor for grading comments.
enable edit of name for stuff management
allow stuff to edit students details
correctes spelling mistake "staff" -> "stuff"
separate the sidebar into 2 regions, for normal user & staff/admin.
fixed resource loading error when customised theme incorrect
add last_commented to std_ans, add std_course_id to std answers.
add list of comments.
add std_course_id index in std answers table.
remove comment count on the sidebar -- wrong one.
adding multiple file uploads control
add sbm_answer to std_coding_answer.
student now receive extra exp when revise trainings.
auto login app if Facebook is connected
welcome page refactoring
multiple files upload for missions and training
Merge branch 'master' of github.com:Coursemology/coursemology.org into development

Conflicts:
	app/controllers/submissions_controller.rb
	app/controllers/trainings_controller.rb
	app/views/submissions/show_question.html.erb
	db/schema.rb