Added my first stab at native.BitmapData.threshold() function. Still has some small glitches (inconsistent results with flash's, could be optimized).
BitmapData.threshold seems accurate now, and decently fast, too!
cpp BitmapData.threshold() now passes these tests:

-Basic functionality
-Decently optimized for straight "==" palette swapping
-Returns same # of pixels changed as flash target
-Returns same visual output unless you mess with destPoint
(will figure out destPoint later)
Forgot a line!
Fixed return value on threshold(), also destPoint seems to work now
TravisCI: basic skeleton of supporting test in plain haxe and in NME.
TravisCI cleanup.
 - TestRunner.hxml only compiles, but not run the test.
 - use "-64" to enable -D HXCPP_M64 on the tests.
 - ignore the test output dir "bin"
TravisCI: forgot to mkdir for output...
TravisCI: fixing 32-bit vs 64-bit
Revert "TravisCI cleanup."

This reverts commit 69750b249c77b56e09fa15df6a84fa9cee1b6b77.
I think BitmapData.threshold() is finished now!
TravisCI: minor
TravisCI: fixing process problem.
TravisCI: NME command-line "-DHXCPP_M64" should be one word.
Merge branch 'fixing'

Conflicts:
	tools/unit-test/nmetest/TestRunner.hx
TravisCI: should run the test...
html5: fixed BitmapData.getInt32, now returns Int32 instead of Int31.
TravisCI: basic BitmapData testing
threshold(): Changed Int32 -> Int for Haxe 3 compatibility; Added Memory.select(null) at end of function calls.
Removed command-line.n. Not sure how that got there.