adding setters to ECSDefaults.java

While this class provides a mechanism to set global defaults for a JVM 
process (through a properties file), it does not provide any means of 
modifying these values pro grammatically.  By adding setters to this 
class, one can do things like turn on pretty_print for an entire 
document rather than element by element.  In addition, this would allow 
for temporary modifications at runtime, whereas the current approach is 
limited to static definitions established at JVM startup.

One other note: since these are simple additions to the class, there is 
no risk.  No current interface or processing is changes at all.  This 
proposal is simply to allow the setting of these values at runtime.

Any thoughts are welcomed.  I have a patch prepared should this change 
be found to be acceptable.

Thank You.
Greg Shah