Configuration mods to allow embedded apps to change font base path in userconfig

[Brian O'Kelley <bo...@cetova.com>]

Hi all,
 
Sorry in advance if I'm not doing this right, it's my first official
contribution (or attempt thereof) to FOP!
 
I ran into issues where my servlet was getting installed and run from a
number of locations, making the relative paths in fop-userconfig.xml not
work, so I made a couple of minor modifications to make this something
the user can configure.
 
1. I added  "getBasePath" and "setBasePath" methods to
configuration/Configuration.java, both in a static context
2. I updated configuration/FontInfo.java to call these methods when
returning font paths
 
I also made a couple of other mods that seemed to make sense.
 
3. I changed Configuration.java to use a singleton pattern instead of
static methods to make future conf migration easier (so that the same
JVM could in theory have multiple Configurations by removing the
singleton - now each Configuration can stand on its own). I added static
helper methods to ensure backwards compatibility.
 
4. In apps/Driver.java, I changed the "ERROR - no logger set" message to
"ERROR - no logger set - using System.out" just for clarity (I was
confused until I saw the source code).
 
I'm attaching a cvs diff of my changes (against the fop-0_20_3 tag). I
think this is the right thing to do, let me know if it's not.
 
If it's useful, I can make these changes work from the command line, or
go ahead and refactor the Options to not be JVM-global - just depends if
folks are interested. I guess this would make sense on the latest dev
branch, not the 0.20.3 branch.
 
Brian