E3-379: Expand substitution/template files within driver.makefile

This should allow .db files to be expanded automatically as a part of the build process instead of each wrapper repo needing to manage it on its own. Note that you can verify that the code to do this is essentially identical in every repository that does it.

Furthermore, it also will expand the .substitution/.template files into O.${BASEVERSION}_Common instead of the source folder, making it easier to tell when a repository is clean.

Finally, and best of all: it does it in a way that requires no changes in the wrappers at all.

(Caveat: if you install for require 3.4.1 then for this version, then you will get the following sort of warning:

/epics/base-7.0.5/require/e3_385/tools/driver.makefile:857: target `/home/simonrose/data/git/e3/modules/e3-cfhvms/cellMods/base-7.0.5/require-e3_385/cfhvms/master-2/db/HVSubstation8.db' given more than once in the same rule.

taevaC)