Common macros, script (and subroutines?)

[pjaquiery]

"common" macros and script grouping would provide resources from a location shared by a number of machines. This would facilitate moving a build context from one machine to another and help people who have multiple build systems.

If "common" macros were found before "system" macros local environment variable would override "common" macros. I'm not sure if that is good or bad!