Add build toolchain to upload LibreOffice API to Maven Central

Set up the toolchain to create sources and javadocs artifacts in
addition to JARs created during the build. Use Buck build tool for
that: [1]. This is a fork of Google's build tool Blaze, created by
Xooglers at Facebook. This build tool (like Blaze itself) uses
Python to write build files.

Add needed tools and build files to install LibreOffice API artifacts
to local Maven repository or deploy them to Maven Central.

To build all needed artifacts LibreOffice must be built regularly
with GNU make first. To build the rest of the API (sources and
javadocs):

  $> buck build api

To replace version number with upcoming release version:

  $> solenv/bin/version.py 5.1.0

To install the API to local Maven repository:

  $> buck build api_install

To deploy the API to Maven Central:

  $> buck build api_deploy

Detailed documentation is added to document the prerequisites and
the workflow to upload LibreOffice API to Maven Central.

* [1] https://buckbuild.com

Change-Id: Ibdd552a01110836703bc069abe829b9921491cac
Reviewed-on: https://gerrit.libreoffice.org/20343
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
(cherry picked from commit 1fd41f43eb73c373cb94d32d82c5fb7a7e243367)
Reviewed-on: https://gerrit.libreoffice.org/20814
Reviewed-by: David Ostrovsky <david@ostrovsky.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>
(cherry picked from commit 95fe7d0a68c230df13c80dd8759f86d635c48101)

1 files changed, 2 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
index 3af6d8f1b2b1..df4429449094 100644
--- a/.gitignore
+++ b/.gitignore
@@ -20,6 +20,7 @@
 #
 
 # where stuff is built
+/buck-out
 /instdir
 /instdir_for_build
 /workdir
@@ -75,6 +76,7 @@
 \#*
 *.kdev4
 .kdev_include_paths
+.buckd
 .directory
 
 # things below this point are targeted for elimination