Refactored xls-writer into a more abstracted library
Added constraint sheets to excel document
removed useless comments
Added association between constraint and module, submodules and programs
Refactored xls & xgls lib structure
Catalog controller doesn't try anymore to parse an xls file when no one is given
Added entities classes with basic intializators
Constraint checker now check prerequisites
Constraint checker now check prerequisites
Removed useless stuff & added simplemethod to create course object from course model
Added devise user model, user catalog & many-to-many r. (pick)
Added join table between courses and user catalogs
Constraint checker now check if prerequisite are valid
Added corequisite check into constraint checker
Credits are now added to course object
Added Submodule constraint object
refactored architecture & added entity & course basic methods
Added course tests
Added p_module class & p_module tests
Added PropertyConstraint class & tests