SERVER-9878 Add type checks to V8 C++ bindings

The main focus of this ticket is tightening up input validation in
our V8 bindings. Doing this required normalizing the way we create
custom types in JS that have special C++-driven behavior. All special
types now use FunctionTemplates that are attached to the V8Scope object.
This allows us to test if an object is of the correct type before using
it.

Other related tickets partially addressed:
SERVER-8961 Differences in argument validation of custom types between v8 and Spidermonkey
SERVER-9803 Handle regular expression parse errors without seg faulting

Conflicts:

	jstests/constructors.js
	src/mongo/scripting/engine_v8.cpp

Conflicts:
	src/mongo/scripting/v8_db.cpp
SERVER-8926 Remove extra error text and 'L' line number prefix
SERVER-10313: uassert if null char in js field names
SERVER-10313: uassert number conflict fix
Make "bare assert" check more selective

Do not trigger "bare assert" error when " assert(" appears in a
quoted string, as it does in src/mongo/shell/mongo.cpp for example
(as generated by the Visual Studio build).
moved kMaxJsFileLength out of header

taken from d389aca upstream
Enhancements to BSONObjBuilder family of classes' stream API

Conflicts:
	src/mongo/bson/bsonobjbuilder.h