Simple implementation of mappedGet for Issue #38.
Fix for arrays being updated too often
Remove debugger statement
Fix throttle behavior
Reduce async timeout
Bumped version to 2.4.1 and rebuilt
Slightly shorter unionArrays

Was fiddling around with unionArrays to see if I could come up with any improvements and this is what I was able to come up with.

Unless I've missed something it should work the same as the original with the following differences:
- Supports an arbitrary # of arrays as input
- Should be a little faster
- Should be a little smaller (242 vs 255 bytes, not including the length of the original attribution)
- Should be a little smaller minified (158 vs 145 bytes using closure compiler)



Performance test:
http://jsperf.com/merge-arrays/4

Quick test at:
http://jsbin.com/ivayet/1/edit
Added tests for Issue #137
Added fix for Issue #137
Fixed #145: resetDefaultOptions doesn't copy _defaultOptions.observe