remove wscript so that there is only one way (gyp) to compile node-sass

wscript

-import Options
-from os import unlink, symlink, popen
-from os.path import exists
-
-srcdir = "."
-blddir = "build"
-VERSION = "0.0.1"
-
-def set_options(opt):
-    opt.tool_options("compiler_cxx")
-
-def configure(conf):
-    conf.check_tool("compiler_cxx")
-    conf.check_tool("node_addon")
-    conf.env.libsass_compiled = exists("./libsass/libsass.a")
-
-def build(bld):
-    if bld.env.libsass_compiled == False:
-      bld.exec_command("cd ../libsass;make")
-  
-    obj = bld.new_task_gen("cxx", "shlib", "node_addon")
-    obj.uselib = "sass"
-    obj.target = "binding"
-    obj.source = "binding.cpp "
-    obj.use = ['LIB_SASS']
-    obj.add_obj_file("./libsass/libsass.a")