validate reactor messages (#2711)

* validate reactor messages

Refs #2683

* validate blockchain messages

Refs #2683

* validate evidence messages

Refs #2683

* todo

* check ProposalPOL and signature sizes

* add a changelog entry

* check addr is valid when we add it to the addrbook

* validate incoming netAddr (not just nil check!)

* fixes after Bucky's review

* check timestamps

* beef up block#ValidateBasic

* move some checks into bcBlockResponseMessage

* update Gopkg.lock

Fix

```
grouped write of manifest, lock and vendor: failed to export github.com/tendermint/go-amino: fatal: failed to unpack tree object 6dcc6ddc143e116455c94b25c1004c99e0d0ca12
```

by running `dep ensure -update`

* bump year since now we check it

* generate test/p2p/data on the fly using tendermint testnet

* allow sync chains older than 1 year

* use full path when creating a testnet

* move testnet gen to test/docker/Dockerfile

* relax LastCommitRound check

Refs #2737

* fix conflicts after merge

* add small comment

* some ValidateBasic updates

* fixes

* AppHash length is not fixed

test/docker/Dockerfile

@@ -14,6 +14,7 @@ ENV GOBIN $GOPATH/bin
 WORKDIR $REPO
 
 # Copy in the code
+# TODO: rewrite to only copy Makefile & other files?
 COPY . $REPO
 
 # Install the vendored dependencies
@@ -21,16 +22,18 @@ COPY . $REPO
 RUN make get_tools
 RUN make get_vendor_deps
 
-# Now copy in the code
-# NOTE: this will overwrite whatever is in vendor/
-COPY . $REPO
-
 # install ABCI CLI
 RUN make install_abci
 
 # install Tendermint
 RUN make install
 
+RUN tendermint testnet --node-dir-prefix="mach" --v=4 --populate-persistent-peers=false --o=$REPO/test/p2p/data
+
+# Now copy in the code
+# NOTE: this will overwrite whatever is in vendor/
+COPY . $REPO
+
 # expose the volume for debugging
 VOLUME $REPO