Add the Kagome tokenizer for Japanese
Add tests for the Kagome tokenizer
Update README.md

Fix broken example.
Merge pull request #99 from jingweno/patch-1

Update README.md
Use byte positions instead of character positions
relocated kagome tokenizer and introduced ja analyzer
Merge branch 'master' of github.com:blevesearch/bleve
added build tag to fix runngin tests without tag
modified token filters to avoid creating new token stream

often the result stream was the same length, so can reuse the
existing token stream
also, in cases where a new stream was required, set capacity to
the length of the input stream.  most output stream are at least
as long as the input, so this may avoid some subsequent resizing
text analysis now moved out of index write lock onto goroutine

1. text analysis is now done before the write lock is acquired
2. there is now a pool of analysis workers
3. the size of this pool is configurable
4. this allows for documents in a batch to be analyzed concurrently

as a part of benchmarking these changes i've also introduce a new
null storage implementation.  this should never be used, as it
does not actualy build an index.  it does however let us go
through all the normal indexing machinery, without incuring
any indexing I/O.  this is very helpful in measuring improvements
made to the text analsysis pipeline, which are often overshadowed
by indexing times in benchmarks actually building an index.
added support for tracking index stats and exposing via expvar

closes #83
better String() impl when request.Size=0
closes #107
fix compliation with the latest changes to kagome
allow term searches for numbers
closes #108
improve lexer handling of special characters

characters like + and - are special
but they should only be special at the beginning of strings
inside someting that would otherwise be a string we should just
let them be characters
closes #103
added ability to return all document fields by requesting field *
renamed unicode_word_boundary package to icu

this is in preparation of alternative unicode word boundary impls
added benchmark for tokenizing English text
added pure go tokenizer to do unicode word boundary segmentation
new pure go porter stemmer integrated

renamed original libstemmer porter to "stemmer_porter_classic"
new pure go stemmer is "stemmer_porter"