add hist2d function (2-dimensional histogram)
added isela function, removed redundant functions: isinteger, isreal, iscomplex, isbool.
renamed integer_valued, real_valued, float64_valued
rename isinteger/realvalued -> isinteger/real, isela -> iseltype
merge remote
remove a couple more redundant intrinsics
a bit more about isequal() and floats in the manual
Shut down all named pipes and tcp streams in jl_close_uv.
Add a test for shutdown being called twice.  Unfortunately it hangs rather than fails.
Stop using libuv's flags, check in jl_close_uv if close has already been called from julia
Change is_open to isopen
Merge pull request #3026 from JuliaLang/jn/linalg_additions

hist2 implementations
Test handle type before testing writable
If a shutdownable stream is not writable, don't call uv_close on it.
use sturges() in hist2d
make strftime and strptime use TmStruct instead of a number, which fixes #2986
plus documentation
add cglobal(sym, type=Void)::Ptr{type}. closes #1815
add array methods for isinteger, isreal, isfloat64
missing methods for isfloat64
fix #3085
fix #3086, performance of quoted functions in AST