- depend on gnc-vcs-info.h file directly instead of the gnc-vcs-info target
The latter won't cause gnucash to update the manpage in case gnc-vcs-info.h changes,
the former does.
- use GNC_VCS_REV as version instead of the static VERSION parameter
This simplifies a number of escape sequences.
The generated file to configure the man page was split up a bit further:
- code that extracted the GNC_VCS_REV_Y_M from gnc-vcs-info.h was spun out
into its own function that now sets all parameters in gnc-vcs-info.h
as environment variables.
- this function is now invoked by configure-manpage.cmake to extract
the date to insert into the manpage.
- the manpage in addition now shows the full date rather than only
yyyy-mm. This is how man itself does it as well.
There are more, but these are most common ones.
There are also a number of urls that don't behave well when https, so those are skipped
At some point I have also started marking non-working URLs as [DEAD LINK], though
that's not a full coverage.
This effectively replaces the use of GNUCASH_BUILD_DATE with GNUCASH_SCM_REV_DATE.
The latter is extracted from the current commit if building from some kind of vcs
(currently only works correctly for svn and git). The info extracted while building
from vcs is then also added to the dist tarball so it's available when building
from tarball as well (via the file libgnucash/core-utils/gnc-vcs-info.h).
The same date is also used to set the date in gnucash' man page document.
A practical detail: I have changed the substitution variables in the man page template
from @- -@ to ${} so we could leverage CONFIGURE_FILE in cmake. The necessary
related adjustments have also been made to Makefile.am's substitution rules.
