typechecker: more uniformity in 'member not found' errors

Summary: Point to the declaration of the class in which the member
 wasn't found for static member access, as well as non-static member
 access. Reorder the message such that the hint (e.g. did you mean)
 comes immediately after.

Reviewed By: @jwatzman

Differential Revision: D1649908

Signature: t1:1649908:1414794120:0b9e4be0e862f4e13644c2c8e922491c24f0ba6a
typechecker: add imemoizeparam to list of autoimports from HH namespace

Reviewed By: @paroski, @jwatzman

Differential Revision: D1649940

Signature: t1:1649940:1414793639:1e5e851cc50efc8c294b2cedb793210de6082bf7
typechecker: improve instanceof handling

Summary: * disallow `instanceof parent|self|static` outside of class
 * interpret `instanceof parent|self|static` as the decoded
   class corresponding to those constructs, as opposed to
   the mythical <?php class Parent|Self|Static
 * in a condition context, passing a generic `instanceof $x` should
   imply an object ... this is strictly speaking not correct if
   `$x` can resolve to `Traversable`, `Stringish`, or some other
   interface that accepts non-object types, but those are all
   hardcoded into the typechecker and should not be observed

Reviewed By: @jwatzman

Differential Revision: D1649177

Signature: t1:1649177:1414793850:129ec1756e90bd1096320dabf3e550729e412419
Remove several raise_warning()'s from user-file.

Summary: Remove several raise_warning()'s from user-file.cpp to match PHP5 behavior.

Passing vfsstream test cases.
Closes https://github.com/facebook/hhvm/pull/4099

Reviewed By: @ptarjan

Differential Revision: D1647139

Signature: t1:1647139:1414799868:94d01e3bbb60a306eb64d275c7125dcdcbbe2f64