Backport all build-related commits from master to stable-0.2

This is a squash of the following commits that are required to
make gitiles buildable with the latest bazel:

9374f0a - Remove bazel-genfiles from .gitignore
bd0c596 - Use bazelisk as first choice for mvn.sh
9d5cb21 - Replace references to bazel-genfiles with bazel-bin
268d677 - Bazel: Bump bazel version to 1.0.0
03cd750 - Bazel: rules_python must be loaded now
10641da - Upgrade bazlets to latest master revision
06d3ee0 - Bazel: Introduce .bazelversion and update to 0.29.1
3de4f96 - Format all build files with buildifier
a267c30 - Bazel: Add fixes for --incompatible_load_java_rules_from_bzl
4d4432d - Upgrade bazlets to latest master revision
422d67a - Align Eclipse settings with Eclipse 2019.06
008bf1b - Update bazlets to latest revision on master

Change-Id: I4894d7beee21a0ea4bfd92c6ce3c6bf6477ef639

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 1d6e531..883ec60 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,20 +3,32 @@
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(
+    name = "rules_python",
+    sha256 = "e5470e92a18aa51830db99a4d9c492cc613761d5bdb7131c04bd92b9834380f6",
+    strip_prefix = "rules_python-4b84ad270387a7c439ebdccfd530e2339601ef27",
+    urls = ["https://github.com/bazelbuild/rules_python/archive/4b84ad270387a7c439ebdccfd530e2339601ef27.tar.gz"],
+)
+
+http_archive(
     name = "bazel_skylib",
     sha256 = "bbccf674aa441c266df9894182d80de104cabd19be98be002f6d478aaa31574d",
     strip_prefix = "bazel-skylib-2169ae1c374aab4a09aa90e65efe1a3aad4e279b",
     urls = ["https://github.com/bazelbuild/bazel-skylib/archive/2169ae1c374aab4a09aa90e65efe1a3aad4e279b.tar.gz"],
 )
 
-load("@bazel_skylib//lib:versions.bzl", "versions")
+# Check Bazel version when invoked by Bazel directly
+load("//tools:bazelisk_version.bzl", "bazelisk_version")
 
-versions.check(minimum_bazel_version = "0.19.0")
+bazelisk_version(name = "bazelisk_version")
+
+load("@bazelisk_version//:check.bzl", "check_bazel_version")
+
+check_bazel_version()
 
 load("//tools:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "2c9d995f712f6531e45756f80431b460c6183f8d",
+    commit = "bf900bbe58f7a7802799d6d6477567b05ab2f399",
     # local_path = "/home/<user>/projects/bazlets",
 )