Add table css in lans.css.scss

Add table cell border formats.
Modify the field type of static_ip_start and static_ip_end in table vlans.

1. Change their their original integer type to string typle by rolling back the db.
2. Modify the ipams-tables20141020a.xls accordingly.
Resolve format conflict in lans.css.scss.
Create the page layout in application.html.erb.
Initial implementation of table vlans.
Merge branch 'vlans' into develop

1. Merge branch welcome, the portal and initial layout.
2. Merge Li Jia's table border css code from lans.css.scss.
3. Initially implement VLAN creation and display.

Conflicts:
	app/controllers/vlans_controller.rb
	app/views/lans/show.html.erb
	architecture/ipams-tables20141020a.xls
	db/schema.rb
	test/fixtures/vlans.yml