doesn't have a default value like the "-config" options of other
openssl subprograms.

file name for 'ca' to come from the environment.

this stuff.

according to the sources.... found by Steffen Dettmer <steffen@tfh-berlin.de>.

shouldn't again start with thousend little text files or we quickly come back
to the old SSLeay days ;-)

make 'req' check the config file syntax before it adds extensions. Added
info in the documentation as well.

info will come later...

Feel free to reformat and tidy this up...