Add Julia translation of psifn from SLATEC with interfaces di-, tri- and polygamma. Also adding some unicode constants
Add disassembly to machine code

- FuncMCView wraps the memory block in MemoryObject interface.
- The slightly tricky thing is to get the in-memory size of the final
asm. This is not exposed by the ExecutionEngine, but conveniently it is
stored already in jl_jit_events FuncInfo structure.
- Uses MCDisassembler, implementation directly derived from code in
llvm-mc.
Added support for sshflags to addprocs. start_remote_workers fixed to support NATed hosts
sshflags is of type Cmd
delete / out of order dequeue on PriorityQueue
added tests for priorityqueue dequeue out of order
Merge pull request #3233 from JuliaLang/anj/psifn

Add Julia translation of psifn from SLATEC and some unicode constants
Add invdigamma function and tests
Correct beta function for negative arguments. Correct documentation for lgamma and lbeta. And some tests.
Merge pull request #3285 from amitmurthy/master

Closes #3281
Merge pull request #3290 from JuliaLang/anj/fixmath

Correct beta function for negative arguments.
small optimization to bitarray getindex
Merge pull request #3284 from ihnorton/disasm

RFC: Add disassembly to machine code
isprime: fix precedence bug.
fix endof(SubString) and write(io, SubString)
Merge branch 'master' of github.com:JuliaLang/julia
throw KeyError on nonexistent key
syntax error for ccall used as an identifier. ref #3289
Merge pull request #3286 from tanmaykm/tanmaykm

delete / out of order dequeue on PriorityQueue
error for global or local in value position. fixes #3271