Update opencart.sql

added missing default layouts
https://github.com/opencart/opencart/issues/2372
https://github.com/opencart/opencart/issues/2363
Merge pull request #2369 from CoverUp/patch-5

Update opencart.sql
extension installer changed for renamed directories
Merge branch 'master' of https://github.com/opencart/opencart
Updated version number for release.
Updated version # to rc version.
Remove laguage string duplicated
Merge pull request #2386 from ManoelVidal/patch-2

Remove language string duplicated
Remove language string duplicated
Merge pull request #2387 from ManoelVidal/patch-3

Remove language string duplicated
Merge remote-tracking branch 'upstream/master'