Update JavaRouting.md

AFAIK 'PATCH' method is also supported, so routes config should allow it.
Fixing minor typo
Read some server configuration from a file

First part of #3429.

Some of the generic server configuration is now read from a
server-reference.conf file. Moved lots of error checking,
validation, system property reading and default values out
of code and into the config file. This change preserves
existing behaviour. All existing system properties still
work.
Support non-standard scala binary versions
Merge pull request #3735 from pvlugter/dependency-cross-version

Support non-standard scala binary versions
Merge pull request #3693 from richdougherty/server.conf

Read some server configuration from a file
Wait for Akka HTTP server to start
Merge pull request #3725 from msavoury/master

Fixing minor typo
Share logic from NettyResultStreamer with Akka HTTP backend

This fixes some tests in ScalaResultsHandlingSpec. Unfortunately
there is still no support for explicit chunked encoding in the
Akka HTTP backend.
Merge pull request #3738 from richdougherty/akka-http-integration-pt2

Akka HTTP backend fixes
Merge pull request #3456 from botchniaque/patch-1

Update JavaRouting.md