SERVER-7902 added support for global /etc/mongorc.js

The corresponding Windows path is
%SYSTEMROOT%\system32\drivers\etc\mongorc.js
SERVER-6400: do not use IN since its a macro on windows
Add support for checking if a mutable Element is numeric
Add function to check if a mutable element is an integral type
Rename SetModifier to ModifierSet
Refactor update SConscript
SERVER-7902 Visual Studio -- add library to SpiderMonkey build
SERVER-7174 SERVER-6400 Visual Studio -- add new files
SERVER-7174 $unset update mod built over the new mods framework.
SERVER-7174 clean commented out code portion.
SERVER-7174 Visual Studio -- add modifier_unset files
SERVER-9605 Use correct string length in hexToBinData()

Do not use hard-coded length of 16 to process variable length hex string.
SERVER-8046 Fixed missed appendElement call implementation.