adjust linker invocation for msvc

skip flisp unit test with msvc (for now?)

skip a few headers (will need to find replacements for these)
Work to get basic REPL to compile with MSVC

explicit casts and fix ifdefs (__WIN32__ => _WIN32)

remove unistd header already included in repl.h

remove DLLEXPORT from repl.h

use hex code for escape

put back getopt.h

define dirname and PATH_MAX for repl

fix LDFLAGS that MSVC doesn't understand

skip julia_res.o with msvc

extern C linkage on repl
REPL now compiles with MSVC

crashes immediately, but it's a start

extern C on basename, dirname, jlapi

DLLEXPORT on basename, dirname

add export to link command for jl_setjmp and jl_longjmp

get uv to export symbols