contains direct subdirectories, otherwise automake < 1.9 fails. Thanks to
Bernd Machenschalk for the hint.
- Made manpages in doc/Makefile a conditional subdirectory, see "7.2.2
Conditional subdirectories with AM_CONDITIONAL" in the automake manual.
- Made manpage creation dependent on the AM_CONDITIONALs ENABLE_CLIENT,
BUILD_CLIENTGUI and ENABLE_SERVER to create only those manpages whose
binaries are going to be compiled.
svn path=/trunk/boinc/; revision=13842
David Anderson