EH doc tweaks

[Jason Merrill]

The note at the top of page 3 says that there are no plans to interoperate
with Java; I believe that has changed.  Similarly, it seems 12.2 should be
updated.

3.7/1, page 6: "The interpretation of this language-specific routine":
  "routine" should be "portion" or "information".

  Also "language-specificdata area" is missing a space.

5.2.1/1, bottom of page 11: "This storage must persists" should be "persist"

5.4/3, p14: "related to" is not normative; perhaps "the __type_info object
  may be of a type derived from std::type_info"?

5.5, p15: "best possible one action" should be "best possible action"

6.1, p18: "end_catch(exception)" is missing the initial "__".
BTW, we had said that these functions would not be mangled, but you have
overloaded __end_catch.

More as I keep reading...

Jason