panama repo summer cleaning

[Maurizio Cimadamore]

Hi,
after some internal discussions, I've decided to clean up the panama 
repository a little bit. Two branches have been removed:

* array2
* vectorSnippets

These branches were no longer being worked on - and it was confusing for 
them to show up in 'hg branches' (especially for the vector one).

I've also disabled our automerge infra on all vector branches - this is 
because merge of the vector branches involve quite a bit of intricate 
changes, so it's best to leave the decision to the experts. Conversely, 
all the foreign branches (foreign, foreign-memaccess, linkToNative and 
foreign+linkToNative) will keep the automerge on, since it's relatively 
smooth there.

Cheers
Maurizio