Fix for #356, multiple class adapted for the feature.

[perilbrain]

(fix for #356)

• Accepts new annotation for collection type.

Hey I have made a few improvements to fix the issue. All tests cases are passing but I definitely need a review for this commit.

[cowtowncoder]

Ah, this looks good I think; I will try to go through with it in more detail, but wanted to mention that this is on my radar for things to go in 2.10 (but I'm also bit overload with all changes :) ).

Only one more question: have I already asked for CLA? If not, it's here:

https://github.com/FasterXML/jackson/blob/master/contributor-agreement.pdf

and we'd need a filled copy before first merged contribution (apologies if I have already asked and gotten one). Easiest way usually is to print it, fill & sign, scan, email to info at fasterxml dot com.