NaCl docs: fix a few more issues with the ARM sandbox documentation.

native_client_sdk/src/doc/reference/sandbox_internals/arm-32-bit-sandbox.rst

 ==================
 ARM 32-bit Sandbox
 ==================
 
-Native Client for ARM is a method for running programs---even malicious
-ones---safely, on computers that use 32-bit ARM processors. It's an
-extension of earlier work on Native Client for x86 processors. This
-security is provided with a low performance overhead of about 10% over
-regular ARM code, and as you'll see in this document the sandbox model
-is beautifully simple, meaning that the trusted codebase is much easier
-to validate.
+Native Client for ARM is a sandboxing technology for running
+programs---even malicious ones---safely, on computers that use 32-bit
+ARM processors. The ARM sandbox is an extension of earlier work on
+Native Client for x86 processors. Security is provided with a low
+performance overhead of about 10% over regular ARM code, and as you'll
+see in this document the sandbox model is beautifully simple, meaning
+that the trusted codebase is much easier to validate.
 
 As an implementation detail, the Native Client 32-bit ARM sandbox is
 currently used by Portable Native Client to execute code on 32-bit ARM
 machines in a safe manner. The portable bitcode contained in a **pexe**
 is translated to a 32-bit ARM **nexe** before execution. This may change
 at a point in time: Portable Native Client doesn't necessarily need this
 sandbox to execute code on ARM. Note that the Portable Native Client
 compiler itself is also untrusted: it too runs in the ARM sandbox
 described in this document.
 
@@ skipping 872 matching lines @@
 ^^^^^^^^^^^^^^
 
 By now you're itching to see the sandbox validator's code and dissect
 it. You'll have a disapointing read: at less that 500 lines of code
 `validator.cc
 <http://src.chromium.org/viewvc/native_client/trunk/src/native_client/src/trusted/validator_arm/validator.cc>`_
 is quite simple to understand and much shorter than this document. It's
 of course dependent on the `ARMv7 instruction table definition
 <http://src.chromium.org/viewvc/native_client/trunk/src/native_client/src/trusted/validator_arm/armv7.table>`_,
 which teaches it about the ARMv7 instruction set.