Improve renaming of pfSense in non-pfSense builds.
As discussed in "Minor issues with "non-pfSense" rename logic", having to rename pfSense files in non-netgate builds is not as smooth as it could be. Manual editing of a few files is necessary during these builds.
Making a few changes in builder_common.sh and in sysutils/pfsense-repo/makefile help avoid the manual editing.
Two pull requests have been submitted