Add: support for boolean filters
Fix: set symfony 2.4-dev as a maximum constraint
Fix: the ModelManager should retrieve columns by their phpName (and in an case-insensitive manner)
Merge pull request #10 from K-Phoen/fix-version-requirements

Fix: version requirement for symfony (allows symfony 2.3)
Merge pull request #11 from K-Phoen/dev-boolean-filter

Add: support for boolean filters
Merge pull request #12 from K-Phoen/fix-columns-retrieval

Fix: the ModelManager should retrieve columns by their phpName (and in a...