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
Revert "try to improve the STDIN as IOStream workaround"

This reverts commit 4e8cabc337b4164b176534a85ffcfcd6578f947f.
Revert "make STDIN an IOStream on linux when the input stream is a file"

This reverts commit 64451781dcba91dc7a5b4884afdd5eb4153d9e41.
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.
beginning the redesign to add immutable types and abstract types with fields.
combine AbstractKind, BitsKind, CompositeKind into DataType
this is a save checkin. the first couple files have been converted.
update array storage for new data types
Merge branch 'master' of github.com:JuliaLang/julia into jb/deleteduplicates
Merge branch 'master' of github.com:JuliaLang/julia into jb/immutable
update egal, object_id and field access builtins
Merge branch 'master' of github.com:JuliaLang/julia into jb/immutable
Merge branch 'master' of github.com:JuliaLang/julia into jb/immutable
Merge branch 'master' of github.com:JuliaLang/julia into jb/immutable
Merge branch 'master' of github.com:JuliaLang/julia into jb/immutable
complete RTS changes for jb/immutable to the point where it compiles again
all needed renaming in Base for jb/immutable