3 directories versions divided by semester class homework, go from semester to class is okay but class to homework is not, experimental approach
3 directories versions divided by semester class homework, go from semester to class is okay but class to homework is not, experimental approach
error is fixed but there is another inheritance problem....
2014-11-3
Merge commit 'e14a254a2aad8281f6a17f4a56f7d43b9c8f20d4' into develop

Conflicts:
	db/schema.rb
projects references to directory_class .....
directories relation bug is fixed, before If I created class Algorithm in 2014-fall, 2014-spring directory can reference Algorithm but now it is fixed!
edit, destroy is implemented in each directories
2014_11_04
restore db migrate file
add feature home view login or not
feature modify semester directory view
If classes created, return to direcotry_semester page