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.