Merge pull request #183 from brainopia/remove_multiple_columns

Support removal of multiple columns
Update changelog and version number
Add native dynamic composite decoding.
Merge pull request #184 from nearbuy/optimized-dynamic-composite

Add native dynamic composite decoding.
Made iteration functions of OrderedHashInt to return self as it is expected for a regular hash
Merge pull request #185 from fester/ordered-hash-each-fix

OrderedHashInt/OrderedHash returning self for iteration functions
Support get_range with tokens
Merge branch 'twitter'