Merge pull request #12 from chives/dev

Fixed sorting of columns that do not have 'order' option set
Changed order sort style, now columns will be sorted from negative to positive numbers
Merge pull request #13 from norzechowicz/order-option

Changed order sort style, now columns will be sorted from negative to po...
Fixed doc
Merge pull request #14 from norzechowicz/order-option

Fixed doc
Fixed resolving column default option
Merge pull request #15 from norzechowicz/order-option

Fixed resolving column default option
Updated to symfony 2.2
Merge pull request #16 from norzechowicz/deps

Updated to symfony 2.2
Simplified tests execution
Added symfony/options-resolver to handle column options
Merge pull request #18 from norzechowicz/options-resolver

Added symfony/options-resolver to handle column options
Merge pull request #17 from norzechowicz/tests

Simplified tests execution
[BC] Renamed column options names.
Merge pull request #19 from norzechowicz/options

[BC] Renamed column options names.
Updated composer.json to verson 1.0.0
Updated doc
Merge pull request #20 from norzechowicz/doc

Updated doc
Fixed typo in README
Removed indexing strategies usage from DataGrid.