Fix DeterministicKeyChainTest failing on Windows

Git changes line endings in files to CR+LF on Windows by default, while
protobuf always uses LF. That makes serialization tests fail.
Handle getting a null from getNewParser gracefully
Configure continuous integration using Travis CI.

Builds will be visible at https://travis-ci.org/bitcoinj/bitcoinj
Stop overwriting OP_WRITE when writing in ConnectionHandler c'tor
Configure IRC notifications for Travis CI. Messages will go to #bitcoinj.
When a wallet is added to a block chain that has a lower block height than the chain, try to repair.

Adds a "crash simulation" unit test.