Extend sqrtm to StridedMatrix and complex integer matrices.
Make sqrtm more forgiving to singular matrices.
Benchmark tweaks:

* Added pi_sum_vec to Matlab, Julia and R (disabled)
* Tweaked parseint in perf.R
* Added perf.lua by Francesco Abatte (Needs the GSL Shell)
Revert "Revert "remove some O(n^2) algorithms in the front end" [fix #2270]."

This reverts commit 1396f74efdf9a87d7c2658757f8d2b20885f67c1.
try a different implementation of delete-duplicates
Merge branch 'master' into sqrtm
More sqrtm tests.
perf: Lua corrections and pi_sum_vec in Python (disabled)
perf.lua: fix oversight
perf.R: cache the pi_sum_vec range to match other implementations.
perf.lua: Adding pure Lua variants.
Merge branch 'master' of github.com:JuliaLang/julia into jb/deleteduplicates
pkg: Use triplequoting for Pkg.new()
Merge branch 'topic/pkg-triplequote'
Package up cairo and tk and dependencies from ~/.julia/{Cairo,Tk}
Improve Makefile, Update .gitignore, Update dmgCreator file.
Merge pull request #2246 from GunnarFarneback/sqrtm

Sqrtm improvements.
Avoid temporary allocation in Zip() iteration

Also adds tests
perf.lua: Removed pure Lua variants

... since the GSL and Julia use the same PRNG, and LuaJIT does not.
Pkg: some very basic testing; must be run explicitly.
Pkg: use triple quotes in more places.