Added the lz4 compression library.

High-throughput compression with ok compression level.
Added lz4 to the filter streams.
improved performance of JSON parsing by not copying strings when passing through lambdas
put back default expectJson to not expect ASCII
Added the lz4cli program.
LZ4 filter is now compatible with the official binary format.
Fixed an out-of-bound read error in bit range ops.
Fixed compile error in lz4cli.
Lz4 now uses the correct compression levels.
Removed useless enum in lz4 filter
add missing include
gcc>4.6: fixed syntax for initializer-list in constructors
use std::mutex not boost::mutex
fixed lz4 filter problems with malloc()
Merge branch 'master' of https://github.com/jeremybarnes/jml
LZ4 now properly handles large blocks written to it.
lz4 filter no longer omits chunks of data when compressing.
fixed another use of alloca() in lz4_filter
added large block filter streams test
Merge branch 'master' of https://github.com/jeremybarnes/jml