Fix compile error in JSON sample

Change-Id: I81fc0d4b9c7fd42059ceb94f7cdef36b4b43e7ea
Implements and tests zip libraries and zip library builders. These
are the building blocks for saving the work of a separate
compilation and using the result of dependency compiles in a
current separate compile.

In future changes, when compiling separately, groups of zip
libraries will be indexed and accessed via a library group facade
and the main compiler call path will be adapted to read from this
facade and write to a library builder as compilation proceeds.

Change-Id: I07eaaf1d2dffc221e6e343a772e6acf5a6f93cad
Review-Link: https://gwt-review.googlesource.com/#/c/4921/
Better magic comments at the end of JavaScript fragments in CrossSiteIframeLinker

- Switch to '#' instead of '@' since this changed in the sourcemap spec
- Set sourcemap URL for every fragment, not just the primary one
- Add template variable support to the includeSourceMapUrl config property

Template variables:
  __MODULE__ substitutes the module name
  __HASH__ substitutes the strong name of the fragment
  __FRAGMENT__ substitutes the fragment number

This makes it easier to build a URL that a servlet can resolve to the
right sourcemap file.

Public API changes:
 - New versions of two methods in SelectionScriptLinker
 - Added CrossSiteIframeLinker.getSourceMapUrl()

Change-Id: I2207d2b258df8c1088129017e5039fbfd0edb093
Review-Link: https://gwt-review.googlesource.com/#/c/4891/
Add JSR305 jars into eclipse classpath

Change-Id: I5f7635cb1ea366985eaabe904d66513a7722cd5f
When compiling separately you need fast indexed access to data
in a set of input libraries as well as ResourceOracle adapters
to surface that data to parts of the code base that already
query via a ResourceOracle interface.

To that end this change adds a LibraryGroup and matching
ResourceOracle adapters

Change-Id: Ief132ea019f30758272865bf3a5fe0c25a62d025
Review-Link: https://gwt-review.googlesource.com/#/c/4922/
Use Guava 15 compatible API

The compiler-rebased.jar in tools/lib/jscomp/r1649 still needs to be
updated and com.google.gwt.thirdparty.guava.* removed.

Issue: 8395
Change-Id: I4b1c0690a44f1d3cf34404cf5ef73e3e72ec5358
In the serialization exception message, include the class whose type signature was not found.

Change-Id: I45f1a195b0c5fc567af4bce13c2489baf8b2b18d
Review-Link: https://gwt-review.googlesource.com/#/c/4960/