Version 3.19.0

Deprecated Context::New which returns Persistent.

Added Persistent<T>::Reset which disposes the handle and redirects it to point to another object.

Deprecated WriteAscii and MayContainNonAscii.

Exposed AssertNoAllocation to API.

Performance and stability improvements on all platforms.

git-svn-id: https://v8.googlecode.com/svn/trunk@14603 ce2b1a6d-e550-0410-aec6-3dcde31c8c00