Dissolve top level gitiles-* directories

The current layout of having gitiles-* directories with separate java
source trees dates back to the bad era of Maven, when this specific
layout was necessary to decompose the build into separate pom.xml files.

Moreover, src/{main,test}/java are also Maven artifacts, so that we go
even further and create three top level directories:

* java
* javatests
* resources

Change-Id: I4421096428db1e3de019a9b6c1253217cf7e4fbe

resources/BUILD

diff --git a/resources/BUILD b/resources/BUILD
new file mode 100644
index 0000000..020f145
--- /dev/null
+++ b/resources/BUILD
@@ -0,0 +1,5 @@
+filegroup(
+    name = "web_xml",
+    srcs = ["web.xml"],
+    visibility = ["//visibility:public"],
+)