Merge branch "handlers".

Handlers are objects to interact with a pager or a datagrid.
3 handlers are availables : View (default), jqGrid, JQuery Autocomplete
Improve compatibility with previous releases
Fix test
Add php in requirements
Enable travis-ci build
Fix some insight violations + unit tests
Travis build status + insight medal + packagit downloads
Unused use statement
Fix bad class paths
Move 'route' & 'parameters' options from ViewHandler to PagerView
Improve doc
Change createXXDataGrid() signature in factory
Require pdo_sqlite in dev
Unit tests
New handler BootstrapTypeahead
New handler Flexigrid
New handler Dynatable
New adapter MongoDBDocument + fix dependencies
Minor fixes + cleanup
Refactoring