add make_rules to the module definitions

[rottaran]

These rules are a dictionary of destination file -> array(sourcefile, command, command...). This makes many of the rules in make_body more declarative. The default build rules that are generated in the makefile template shall be skipped when such an explicit rule is given for the same combination of destination and source file. The compile_commands.json can be extended with build information for files that are not covered by our default rules.