bunch of fixes

Allowed proxy classes to include parameters with default values
Fixed caster to use camelize instead of ucfirst
Update and insert commands now support RETURN parameter
Fixed insert to return value (including new rid)
General spacing corrections
Actually I didn't notice the `bin-dir` directive in `composer.json`, it wasn't there the last time I tinkered with the project so I thought it was a leftover from when we were downloading phpunit manually :-) You can just remove `phpunit.phar` for now (it's not used) and we'll eventually discuss in other issues if we should remove `bin-dir` and rely on the default directory for binaries imported by our dependencies (I'd prefer to do so, but this shouldn't be my own decision).

On a related note, in `.travis-ci.yml` the line `script: phpunit --group __nogroup__,integration` should really be `script: bin/phpunit --group __nogroup__,integration` because right now the suite runs on the default `phpunit` binary shipped by TravisCI and not the one we require through `composer.json`.