macros for turning off bounds checks. fixes #1392

`@inbounds expr` allows bounds checks to be omitted for code syntactically
inside the argument expression.

adds @inbounds to matmul, comprehensions, and vectorized binary operators.
Merge branch 'master' of github.com:JuliaLang/julia into jb/inbounds
Merge branch 'master' of github.com:JuliaLang/julia into jb/inbounds
clarify boundscheck expressions
Merge branch 'master' of github.com:JuliaLang/julia into jb/inbounds
Merge branch 'master' of github.com:JuliaLang/julia into jb/inbounds

Conflicts:
	src/alloc.c
	src/codegen.cpp
	src/jltypes.c
Migrated isapprox() to base
Added test suite for isapprox()
Documentation for isapprox()
Removed duplicate definitions of rtoldefault and atoldefault methods
Test and export hooks for isapprox
First cut at changes discussed in issue #3423

This version also needs cleaning (the two cholfact methods defined in the loop should be condensed to one) but I am putting this up for others to see what I meant.
faster readcsv. fixes #3350
Simplified implementation for real nonfloats as well as for complex numbers
Updated documentation for isapprox()
Fixes UVError bug in listen/accept
Merge pull request #3435 from danielmendel/fix-accept-uverror

Fixes UVError bug in listen/accept
Fix bugs in redirection operators

Also make tests use new syntax
Actually give the right deprecation
Merge pull request #3429 from tanmaykm/readcsv

faster readcsv. fixes #3350