fix #2307
make error during showing work a bit more cleanly
rename iostring.jl to iobuffer.jl. should have done that before.
simpler handling of backtrace printing
remove BackTrace and add_backtrace
fix test error reporting to show backtraces from where the error happened, rather than from inside test.jl. done using rethrow()
Faster versions of cor and cov.
Merge branch 'master' into faster-cov
Merge pull request #2311 from tshort/faster-cov

Faster cov and cor
Fixes for cov and cor.
Merge branch 'faster-cov'
Documentation improvements: cleanups and add return type information

Closes #2147
Merge pull request #2313 from tshort/faster-cov

Fixes for faster cor and cov
add conversions between float and int128 types
remove size-specific trunc, sext, and zext intrinsics
DRY up more of the conversion definitions
this requires 'make clean'
fix typo in doc

fix typo in doc
Merge pull request #2323 from wlbksy/patch-2

fix typo in doc