Initial work towards BIP0037 bloom filtering API.
Cleanup and finish BIP0037 bloom filter API.

This commit finishes the work started by @dajohi on bloom filters.

- Rename the package from bloomfilter to bloom
- Rename New function to NewFiler
- Rename Load function to LoadFilter
- Rename BloomFilter type to Filter
- Rename Contains to Matches
- Correct tx match handling to match all inputs and outputs instead of
  only the first one
- Optimize murmur hash function by using constants
- Optimize the merkle block creation and reduce num of memory allocations
  required
- Make MsgFilterLoad concurrent safe as intended
- Update various code consistency issues
- Add a lot of comments
- Improve tests
- Make the code golint clean
Add license header to all bloom package files.
Add a testable example.

This commit creates and an example test file that integrates nicely with
Go's example tooling.

This allows the example output to be tested as a part of running the
normal Go tests to help ensure it doesn't get out of date with the code.
Add godoc reference badge to README.md files.
Use a more specific license adjective in README.md.
Add READEME.md for bloom package.
Really add READEME.md for bloom package.
Add TravisCI build status badge to subpackages.
IMPORT PATH MODIFICATION CHANGESET
----------------------------------

Please use this changeset as the first one on top of the conformal codebase.
Note that if there are new imports, they need to be changed as part of this
changeset. In general, use "git rebase" on github.com/conformal's version
and apply this changeset first.