Merge pull request #68 from vuthao/develop

develop
edit SQL limit
module download: change table nv3_vi_download_comment
optimize code for PHP
optimize code
Merge pull request #69 from vuthao/develop

develop
Add install oracle database
Change admin theme background, theme size, prepare to responsive and retina support.
Add retina for admin default theme
Update admin theme
Merge pull request #5 from nukeviet/develop

develop
fix  css optimezer
Merge pull request #72 from vuthao/develop

develop
optimize code for PDO
change class sql_db
remover funtion show query
 optimize code for oracle database
Optimize code and fix install on step 5
Fix clearsystem
Change font folder and fix CJzip.php