Cleanup layout's HTML
Improved error messages and unit tests in BaseGroupedMapper, fixed CS

Fixed tests for php 5.3
Merge pull request #2412 from dunglas/patch-3

Cleanup layout's HTML
Merge pull request #2411 from pulzarraider/base_group_mapper_impr

Improved error messages and unit tests in BaseGroupedMapper, fixed CS
updated ignore files added idea files to ignore list
Merge branch 'sonata-master'