Rename.
Make the Request a MutableRegistry (closes #263).
Fix the build (#263)

MinimalContext was renamed to ReadOnlyContext in a0717bc.
This updates the manual chapters that had references to MinimalContext.
Specify thread stack size for tests

It's my hope that this will cut down on sporadic errors that we're seeing in Travis CI:
java.lang.OutOfMemoryError : unable to create new native Thread