Create settings form for blocks

[rudolfbyker]

Make blocks such as 'featured nodes' and 'newest nodes' configurable using hook_block_configure. Specifically add options to:

• Limit number of items in the list
• Specify simple links vs. rendered nodes
• Specify the view mode for rendered nodes.
• Ignore or abide by node access.

[rudolfbyker]

If node access checking is enabled, the block should be cached per user, and not globally.