Add isStandard risk analysis.

This is currently only to deal with recent spam, especially dust sybil spam. Includes an unit-test by Andreas Schildbach.
Add method to clean up the wallet.

Currently, it just removes risky pending transaction from the wallet and only if their outputs have not been spent. Includes unit-tests by Miron Cuperman.
PaymentSession: javadoc formatting.
Wallet: recursively kill transactions that depend on dead transactions.

Resolves issue 186.
PaymentSession: some bug fixes and new accessors.
Add a tool to dump payment protocol requests to stdout.
Build a bundled JAR for the core in parallel to the normal unbundled JAR. Helps people who don't use Maven for some reason, like Jython/JRuby users.
Fix handling of defaults when parsing the payment message. Bitpay is leaving out the payment details version which was handled incorrectly. Adds a testcase for the defaults.
Don't throw just because the name of the CA cannot be determined.
Move 30MB seeds.txt out of core and into contrib
Remove seeds.txt (it's too big for git, I think)
SeedPeers reads from smaller addr files for 3 nets

 * Text files for production, test, and unit test
 * Files have IP addresses only
 * 600, 25, and 1 address each respectively
 * Improved implementation and unit tests
Placeholder not needed anymore
copyToCore task to copy to 'core' module resource

Also, change download dir for sipas seeds.txt to builder
Merge branch 'master' into msgilligan-issue457