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

tools/run_dev.sh

diff --git a/tools/run_dev.sh b/tools/run_dev.sh
index ce1afa3..497e9d3 100755
--- a/tools/run_dev.sh
+++ b/tools/run_dev.sh
@@ -26,7 +26,7 @@
 
 (
   cd "$ROOT"
-  bazel build gitiles-dev:dev
+  bazel build java/com/google/gitiles/dev
 )
 
-"$ROOT/bazel-bin/gitiles-dev/dev" $PROPERTIES
+"$ROOT/bazel-bin/java/com/google/gitiles/dev/dev" $PROPERTIES