Updated licence to WTFPL
Added test target on Makefile
Refactored code that sets array boundaries
Renamed last property to cursor
Big refactor to getRange behavior

The aproximate parameters in fetch, get and getRange were removed.
Now, both fetch and get look for an exact match. getRange, on the
other hand, will slice the array portion contained between and
containing both boundaries.
Updated to version 1.2.0