Rename the PROJECT_NAME cinit makefile variable.

res/_cinit/make.tmp
	-Rename `PROJECT_NAME` to `PROJECT_EXECUTABLE`, to more
	accurately describe its later use.
Move _cinit > cinit. Update paths in cinit script.

res/(_cinit -> cinit)/
	-The trailing underscore was superfluous, as it was originally
	only used to distinguish a resource directory inside
	`shell_scripts/`, before they were moved to `res/`.

shell_scripts/cinit
	-Update resource paths accordingly.
Merge branch 'feature/cinit_refactor' into develop

res/(_cinit -> cinit)/
	-Rename the `cinit` resource directory.