Changed Makefile organization to not use data folders because this is simpler and seems to make Make less confused about the need to re-fetch and re-build files. In the future, a better solution to specifying folder targets would be to use order-only-prerequisites (see https://www.gnu.org/software/make/manual/make.html#Prerequisite-Types).
Fixed a bug in the Solano load command. Added and changed a few file and database cleaning targets to makefile.