[Fix] name and placeholder in submission template
[Add] Ignore *.swp files
[Add] create function for submission
[Add] delete for submission
[Fix] Add missing method field to submission model
[Add] edit for submission
[Update] remove length limit from submission templates
[Update] submission models field limit
[Update] submission field length limit and templates
[Update] submission edit's instance condition
[Update] remove redundant comment
[Update] change submission to use forms.py (instead of modelform_factory)
[Update] clean tabs
[Fix] remove wrong and redundant HTML for submission
[Add] submission of slide
[Update] more submission fields and templates
[Update] change submission files code & templates
[Update] change submission templates
[Fix] files action in submission edit
[Update] change submission's file path