trunk-tracking: removed unneeded import
trunk-tracking: include-what-you-use add vector include
trunk-tracking: include-what-you-use add set include
trunk-tracking: minor style fix
trunk-tracking: we depend on r2577 now
psol: updating from r2577
readme: doc depot tools installation
psol: updating from r2618
file_cache: validate FileCachePath
building off r2618
readme: clarify that 'make all' always fails
merge commit: inflating upstream; fix message handler initialization
readme: make now needs a wrapper for the ar command
readme: make all needs AR.foo as well
trunk-tracking: updated release binaries against r2618
trunk-tracking: updated debug binaries against r2618
config: explictily link in the math library
loopback-routing: apply session fetchers

Makes sure we use the LoopbackRouteFetcher, and also wires up AddHeadersFetcher.

Note that this pulls in loopback_route_fetcher.cc from svn revision r2649

The LoopbackRouteFetcher is applied unconditionally, while in mod_pagespeed it
is not applied when one of these configuration settings is true:

* disable_loopback_routing
* slurping_enabled, or
* test_proxy is set

I added a TODO for that.

(Sqash-merge of Otto's #193.)
system-test: infrastructure, host validation

We are going to need some nginx-specific system tests, and this seemed like a
good place to start. This adds two tests, as well as some infrastructure. With

Squash-merge of my #194 and #195
system-test: support blocking rewrites (fixes #199)