Update to gdsfmt_1.1.3

* minor fixes
* support efficient random access of zlib compressed data, which are
composed of independent compressed blocks
* support LZ4 compression format (http://code.google.com/p/lz4/), based
on "experimental lz4frame API" of r124
* include zlib_1.2.8 and LZ4 source codes
* allow R RAW data (interpreted as 8-bit signed integer) to replace
32-bit integer, with 'read.gdsn', 'readex.gdsn', 'apply.gdsn',
'clusterApply.gdsn', 'write.gdsn', 'append.gds'