Remove all bashisms from makefiles

configure/E3/CONFIG

 # -*- mode: Makefile;-*-
 
 # Update the module version (for numeric versions) with a build number of 0 if none is specified
-E3_MODULE_VERSION:=$(E3_MODULE_VERSION)$(shell [[ "$(E3_MODULE_VERSION)" =~ ^[0-9]+\.[0-9]+\.[0-9]+$$ ]] && echo +0)
+E3_MODULE_VERSION:=$(E3_MODULE_VERSION)$(shell (echo "$(E3_MODULE_VERSION)" | grep -Eq "^[0-9]+\.[0-9]+\.[0-9]+\$$") && echo +0)
 
 E3_MODULES_PATH?=$(E3_SITEMODS_PATH)