Add more tests for torch.sort()
Benchmark sort worst case on sorted case
Indent quicksort for improved readability
Test for correct sorting of values and indices
Speed up quicksort

torch.sort() ascending: change choice of pivot to the middle element rather than the first. This avoids the worst-case being on pre-sorted input.
Update benchmark and test for sort descending
Indent quicksort descending for readability
Speed up quicksort descending

torch.sort() descending: change choice of pivot to the middle element rather than the first. This avoids the worst-case being on pre-sorted input.
Remove dependency on unused outside package
Merge pull request #176 from jucor/faster_qsort

Speed-up qsort for sorted arrays
Allow pngcairo if available

This provides nicer-looking png
Add pngcairo to pngfigure()
Uniformize coding style between my two modifications
Document use of terminal pngcairo
openmp for add/mul/div is restricted to only large arrays (arbitrary threshold set to 100k). Also fixes some c89 commenting for the new quick sort algorithms
Merge pull request #178 from 2ndforks/master

openmp for add/mul/div is restricted to only large arrays (arbitrary thr...
Merge pull request #177 from jucor/updated_pngcairo

Add pngcairo if available
Merge remote-tracking branch 'upstream/master'

Conflicts:
	rocks/gnuplot/doc/README.md
torch: moved timeSort.lua around