Adds support for data filters and sorting.
Implements custom functions for type validations. (Travis php5.4 failling on is_int function)
Adds missing invalid messages for type validators.
Fixes: missing exception
Minor fix: collection class only calls repository save method if there is any modified object
Minor fix parsing multiple errors from POST method.
Fixes channel test expecting ServerError exception to expect MultipleServerError since channels have now bulk support.
Tries to fix isInteger validator method
Merge pull request #13 from mobilerider/feature/completes-filter-sort-support

Adds support for data filters and sorting and fixes minor issues