Implementing passing AC/WA info using flash.
Add markdown preview system for views

Using dummy URL for AJAX
Connect to AJAX and render converted markdown
Use POST method instead of GET when using AJAX
close #46 Refact scss
Show markdown preview to be parallel with 'Small Input' textarea
Refactor js code of the timer, close #45.
Merge pull request #47 from TakenokoChocoHolic/#45_RefactorJScodeOfTheTimer

Refactor js code of the timer, close #45.
Merge pull request #44 from TakenokoChocoHolic/42_markdown_preview

42 markdown preview
Add mongoid-paperclip plugin and generate Image model

Conflicts:
	config/routes.rb
Add image uploading function

Conflicts:
	app/views/contests/problems/_form.html.erb
	config/routes.rb
Add message methods to Problem model
Add a message to flash[:solved] according to AC/WA
Display AC/WA message in problem page after submission
Make message methods instance methods to make them more flexible
Add rspec, spork and guard.
Merge branch 'master' into 41_test
Remove unused file
Change <br /> to <br>
Add gems for datetimepicker