clean up javascript

[dbu]

we have 2 similar but different js files init.js and select.js. at least we should rename them to admintree.js and selecttree.js to reflect what is in them. ideally we would manage to extract a common base class or something (me no javascript expert, sorry)

additionally we should provide reasonable defaults for all config options where it makes sense or complain if required options miss, to make this more developper-friendly.

[wouterj]

I'll start working on this one

[lsmith77]

@wouterj there are 2 todos here that maybe you can address while you are at it .. though maybe it requires a different tree lib (which @dantleech was looking into):
https://github.com/sonata-project/SonataDoctrinePhpcrAdminBundle/pull/164/files#L1R167

specifically allowing us to pass in the full name and letting the client cut off (and provide the full name via a tooltip) as well as the client not using a link for nodes that are not editable, so that we do not need to append this hardcoded text.

[wouterj]

@lsmith77 thanks, it seems like both should not be too hard to fix. I'll see what I can do

[dbu]

as @dantleech is proposing to basically replace this bundle with something better after 1.0, i would recommend to only do minimal efforts here.