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
LAPACK wrappers. New QR factorization, subroutines for RFP format and new symmetric tridiagonal eigensolvers.
rename "B" in core.jl tests
fix #2360 (BitArray ref/assign performance)
bitarray: remove some useless definitions
bitarray: change .^ following 1d82980562
fix #2254 again
Merge branch 'master' of github.com:JuliaLang/julia
cleanup conversions to BigInt,BigFloat

This adds a few missing conversions (e.g. Bool->BigInt), promote
rules and constructors. Also adds tests.