Updated Python libraries to work with current Scala libraries in dataframes

[stevebuckingham]

Using point, polygon and polyline types in PySpark was broken due to changes in the Scala libraries, the references now required and how the types were being serialized and deserialized.

These changes are to re-enable dataframe functionality in the Python libraries.

[codecov-io]

Codecov Report

Merging #113 into master will increase coverage by 12.71%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master     #113       +/-   ##
===========================================
+ Coverage    76.7%   89.41%   +12.71%     
===========================================
  Files          42       48        +6     
  Lines        1395     1550      +155     
  Branches      103      106        +3     
===========================================
+ Hits         1070     1386      +316     
+ Misses        325      164      -161

Impacted Files	Coverage Δ
...in/scala/magellan/mapreduce/ShapeInputFormat.scala	90.62% <0%> (-9.38%)	⬇️
src/main/scala/magellan/BoundingBox.scala	93.47% <0%> (-6.53%)	⬇️
src/main/scala/magellan/io/ShapeWritable.scala	55.55% <0%> (-4.45%)	⬇️
src/main/scala/magellan/Line.scala	86.88% <0%> (-4.35%)	⬇️
...scala/org/apache/spark/sql/types/PolyLineUDT.scala	88.88% <0%> (-4.22%)	⬇️
.../scala/org/apache/spark/sql/types/PolygonUDT.scala	93.75% <0%> (-2.55%)	⬇️
src/main/scala/magellan/index/ZOrderCurve.scala	92.68% <0%> (-1.61%)	⬇️
src/main/scala/magellan/PolyLine.scala	89.18% <0%> (-1.09%)	⬇️
...ain/scala/magellan/mapreduce/ShapefileReader.scala	96.15% <0%> (-0.82%)	⬇️
src/main/scala/magellan/index/Indexer.scala	100% <0%> (ø)	⬆️
... and 36 more

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[harsha2010]

@stevebuckingham , were you able to test this on a cluster? Does joins etc on a distributed data frame work in python? Or are more changes needed to fix the python scripts?

[harsha2010]

sbt/sbt clean test is showing me a compilation failure in the python module:

Listing '/Users/kernelfish/projects/magellan/python'...
Listing '/Users/kernelfish/projects/magellan/python/magellan'...
Compiling '/Users/kernelfish/projects/magellan/python/magellan/types.py'...
*** File "/Users/kernelfish/projects/magellan/python/magellan/types.py", line 443
print Point(1,1)
^
SyntaxError: invalid syntax

[stevebuckingham]

I'll update that - I've been compiling on 2.7 and so that is valid. I'll import print from future and update the cost. I've managed within joins between points and polygons but I am having a problem getting intersect to work with polyline and polygon (which I think it should looking at the Scala code). So I suggest you reject this pull request and I can submit a new one when I fox both of the above.