Fall back to fontconfig file based on only OS major version number on Linux

with RHEL 5, Red Hat switched their version scheme from a single number (i.e. RHEL 4) to a <major>.<minor> (i.e. RHEL 5.6). This causes problems because FontConfiguration will expect a different fontconfig file for each update of RHEL.

The solution is to first search for a fontconfig file based on the <major>.<minor> version number and if we don't find that, fall back to a file based on just the major file number. That way we can have a “default” fontconfig for the major release, and add an update specific file if there is a need to override the behavior.

For example, on a Solaris 10 machine (Sun OS 5.10) , it currently would look for the following files in order :

fontconfig.5.10.properties
fontconfig.5.10.bfc
fontconfig.properties
fontconfig.bfc

We want it to also look for a fontconfig file with a name based off of the major version alone:

fontconfig.5.10.properties
fontconfig.5.10.bfc
fontconfig.5.properties
fontconfig.5.bfc
fontconfig.properties
fontconfig.bfc