For reasoning why a transition to autotools is desired, see the commit
message of the previous patch in this series.
"make install" copies the "build", "common" dirs, as well as the "*.xsl"
files to $(prefix)/share/osmo-gsm-manuals. Prefix is typically
/usr/local. Also a pkg-config file gets installed, so the path of the
shared files can be looked up by autoconf scripts of the project
repositories. The check-depends script is installed to
$(prefix)/bin/osmo-gsm-manuals-check-depends and will be used by
project specific autoconf scripts, too.
All existing make targets ("make", "make check", "make upload") are
still working, users only need to run "autoreconf -fi" and
"./configure" beforehand.
Makefile.am uses custom install-data-hook and uninstall-local targets,
so we don't need to specify each file of the relevant subdirs in a
_DATA variable (no extra maintenance effort).
(moving manuals to project repositories 5/19)
Related: OS#3385
Change-Id: I8e7036fae062ee783cb132b14608827a82c5e7c7
Replace TOPDIR with OSMO_GSM_MANUALS_DIR. When the project specific
manuals will be built out of this repository, we still need to refer to
the top directory of the shared content. But it will be in another
repository, so we need to rename the variable to avoid confusion.
(moving manuals to project repositories 3/19)
Related: OS#3385
Change-Id: I2af797546de048a6ab19a5cbc755e5e15575d7ab