writecsv for abstract arrays removed

fix #8675

writecsv method on AbstractArray is now removed (commented).
docs updated.
Added sortperm!

* Allows preallocation (and therefore, reuse) of an index array
* Useful for #8316
remove `evaluate` function for functor types
make rounding modes parametric types
Merge pull request #8790 from JuliaLang/jcb/rm_evaluate

remove `evaluate` function for functor types
Raise informative error for exponentiation to negative power (see #3024)
Merge pull request #8792 from JuliaLang/kms/sortperm!

Added sortperm!
Merge pull request #8784 from JuliaLang/teh/expneg

Raise informative error for exponentiation to negative power (see #3024)
Update helpdb for sortperm!
Merge branch 'master' of github.com:JuliaLang/julia
silence innocuous unused-var warning (with Appple LLVM 6.0)
fix #8768, make `isimmutable` a generic function
dllexport `jl_errorf`. fixes #8732
Merge pull request #8688 from tanmaykm/readcsv

writecsv now only for vectors & matrices fix #8675
fix #8637, error for hash function returning non-Int-sized value
Merge branch 'master' of github.com:JuliaLang/julia
Merge pull request #8794 from simonbyrne/rounding-parametric

make rounding modes parametric types
doc: update getting-started.rst. Fixes #6545
Merge branch 'master' of https://github.com/JuliaLang/julia

* 'master' of https://github.com/JuliaLang/julia:
  doc: update getting-started.rst. Fixes #6545
  fix #8637, error for hash function returning non-Int-sized value
  dllexport `jl_errorf`. fixes #8732
  fix #8768, make `isimmutable` a generic function
  silence innocuous unused-var warning (with Appple LLVM 6.0)
  Update helpdb for sortperm!
  Raise informative error for exponentiation to negative power (see #3024)
  make rounding modes parametric types
  remove `evaluate` function for functor types
  Added sortperm!
  writecsv for abstract arrays removed